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SUMMARY

The Cybersecurity and Infrastructure Security Agency (CISA) and the Norwegian National Cyber Security Centre (NCSC-NO) are releasing this joint Cybersecurity Advisory (CSA) in response to active exploitation of CVE-2023-35078 and CVE-2023-35081. Advanced persistent threat (APT) actors exploited CVE-2023-35078 as a zero day from at least April 2023 through July 2023 to gather information from several Norwegian organizations, as well as to gain access to and compromise a Norwegian government agency’s network.

Ivanti released a patch for CVE-2023-35078 on July 23, 2023. Ivanti later determined actors could use CVE-2023-35078 in conjunction with another vulnerability CVE-2023-35081 and released a patch for the second vulnerability on July 28, 2023. NCSC-NO observed possible vulnerability chaining of CVE-2023-35081 and CVE-2023-35078.

CVE-2023-35078 is a critical vulnerability affecting Ivanti Endpoint Manager Mobile (EPMM) (formerly known as MobileIron Core). The vulnerability allows threat actors to access personally identifiable information (PII) and gain the ability to make configuration changes on compromised systems. CVE-2023-35081 enables actors with EPMM administrator privileges to write arbitrary files with the operating system privileges of the EPMM web application server. Threat actors can chain these vulnerabilities to gain initial, privileged access to EPMM systems and execute uploaded files, such as webshells.

Mobile device management (MDM) systems are attractive targets for threat actors because they provide elevated access to thousands of mobile devices, and APT actors have exploited a previous MobileIron vulnerability. Consequently, CISA and NCSC-NO are concerned about the potential for widespread exploitation in government and private sector networks.

This CSA provides indicators of compromise (IOCs) and tactics, techniques, and procedures (TTPs) obtained by NCSC-NO investigations. The CSA also includes a nuclei template to identify unpatched devices and detection guidance organizations can use to hunt for compromise. CISA and NCSC-NO encourage organizations to hunt for malicious activity using the detection guidance in this CSA. If potential compromise is detected, organizations should apply the incident response recommendations included in this CSA. If no compromise is detected, organizations should still immediately apply patches released by Ivanti.

Download the PDF version of this report:

TECHNICAL DETAILS

Note: This advisory uses the MITRE ATT&CK^® for Enterprise framework, version 13. See the MITRE ATT&CK Tactics and Techniques section of this advisory for a table of the threat actors’ activity mapped to MITRE ATT&CK® tactics and techniques. For assistance with mapping malicious cyber activity to the MITRE ATT&CK framework, see CISA and MITRE ATT&CK’s Best Practices for MITRE ATT&CK Mapping and CISA’s Decider Tool.

Overview

In July 2023, NCSC-NO became aware of APT actors exploiting a zero-day vulnerability in Ivanti Endpoint Manager (EPMM), formerly known as MobileIron Core, to target a Norwegian government network. Ivanti confirmed that the threat actors exploited CVE-2023-35078 and released a patch on July 23, 2023.[1] Ivanti later determined actors could use CVE-2023-35078 in conjunction with another vulnerability, CVE-2023-35081, and released a patch for the second vulnerability on July 28, 2023.[2]

CVE-2023-35078 is a critical authentication bypass [CWE-288] vulnerability affecting Ivanti Endpoint Manager Mobile (EPMM), formerly known as MobileIron Core. The vulnerability allows unauthenticated access to specific application programming interface (API) paths. Threat actors with access to these API paths can access PII such as names, phone numbers, and other mobile device details of users on the vulnerable system; make configuration changes to vulnerable systems; push new packages to mobile endpoints; and access Global Positioning System (GPS) data if enabled.

According to Ivanti, CVE-2023-35078 can be chained with a second vulnerability CVE-2023-35081.[2] CVE-2023-35081 is directory traversal vulnerability [CWE-22] in EPMM. This vulnerability allows threat actors with EPMM administrator privileges the capability to write arbitrary files, such as webshells, with operating system privileges of the EPMM web application server. The actors can then execute the uploaded file.[2]

CISA added CVE-2023-35078 to its Known Exploited Vulnerabilities Catalog on July 25, 2023, and CVE-2023-35081 on July 31, 2023.

CISA and NCSC-NO are concerned about the potential for widespread exploitation of both vulnerabilities in government and private sector networks because MDM systems provide elevated access to thousands of mobile devices. Threat actors, including APT actors, have previously exploited a MobileIron vulnerability [3],[4].

APT Actor Activity

The APT actors have exploited CVE-2023-35078 since at least April 2023. The actors leveraged compromised small office/home office (SOHO) routers, including ASUS routers, to proxy [T1090] to target infrastructure, and NCSC-NO observed the actors exploiting CVE-2023-35078 to obtain initial access to EPMM devices [T1190] and:

• Perform arbitrary Lightweight Directory Access Protocol (LDAP) queries against the Active Directory (AD).
• Retrieve LDAP endpoints [T1018].
• Use API path /mifs/aad/api/v2/authorized/users to list users and administrators [T1087.002] on the EPMM device.
• Make EPMM configuration changes (Note: It is unknown what configuration changes the actors made).
• Regularly check EPMM Core audit logs [T1005].

The APT actors deleted some of their entries in Apache httpd logs [T1070] using mi.war, a malicious Tomcat application that deletes log entries based on the string in keywords.txt. The actors deleted log entries with the string Firefox/107.0.

The APT actors used Linux and Windows user agents with Firefox/107.0 to communicate with EPMM. Other agents were used; however, these user agents did not appear in the device logs. It is unconfirmed how the threat actors ran shell commands on the EPMM device; however, NCSC-NO suspects the actors exploited CVE-2023-35081 to upload webshells on the EPMM device and run commands [T1059].

The APT actors tunneled traffic [T1572] from the internet through Ivanti Sentry, an application gateway appliance that supports EPMM, to at least one Exchange server that was not accessible from the internet [T1090.001]. It is unknown how they tunneled traffic. NCSC-NO observed that the network traffic used the TLS certificate of the internal Exchange server. The APT actors likely installed webshells [T1505.003] on the Exchange server in the following paths [T1036.005]:

• /owa/auth/logon.aspx
• /owa/auth/logoff.aspx
• /owa/auth/OutlookCN.aspx

NCSC-NO also observed mi.war on Ivanti Sentry but do not know how the actors placed it there.

MITRE ATT&CK TACTICS AND TECHNIQUES

See Table 1—Table 7 for all referenced threat actor tactics and techniques in this advisory.

Table 1: APT Actors ATT&CK Techniques for Initial Access

Technique Title	ID	Use
Exploit Public-Facing Application	T1190	The APT actors exploited CVE-2023-35078 in public facing Ivanti EPMM appliances since at least April 2023.

Table 2: APT Actors ATT&CK Techniques for Execution

Technique Title	ID	Use
Command and Scripting Interpreter	T1059	The APT actors may have exploited CVE-2023-35081 to upload webshells on the EPMM device and run commands.

Table 3: APT Actors ATT&CK Techniques for Discovery

Technique Title	ID	Use
Account Discovery: Domain Account	T1087.002	The APT actors exploited CVE-2021-35078 to gather EPMM device users and administrators.
Remote System Discovery	T1018	The APT actors retrieved LDAP endpoints.

Table 4: APT Actors ATT&CK Techniques for Persistence

Technique Title	ID	Use
Masquerading: Match Legitimate Name or Location	T1036.005	The APT actors likely installed webshells at legitimate Exchange server paths.
Server Software Component: Web Shell	T1505.003	The APT actors implanted webshells on the compromised infrastructure.

Table 5: APT Actor ATT&CK Techniques for Defense Evasion

Technique Title	ID	Use
Indicator Removal	T1070	APT actors deleted httpd access logs after the malicious activities took place using string Firefox/107.0.

Table 6: APT Actor ATT&CK Techniques for Collection

Technique Title	ID	Use
Data from Local System	T1005	APT actors regularly checked EPMM Core audit logs.

Table 7: APT Actor ATT&CK Techniques for Command and Control

Technique Title	ID	Use
Protocol Tunneling	T1572	The APT actors tunneled traffic from the internet to an Exchange server that was not accessible from the internet.
Proxy	T1090	The actors leveraged compromised SOHO routers to proxy to and compromise infrastructure. The actors tunneled traffic from the internet to at least one Exchange server.
Proxy: Internal Proxy	T1090.001	The APT actors tunneled traffic from the internet to an Exchange server that was not accessible from the internet.

EVIDENCE OF VULNERABILITY METHODS

CISA recommends administrators use the following CISA-developed nuclei template to determine vulnerability to CVE-2023-30578:

id: CVE-2023-35078-Exposure   info:   name: Ivanti EPMM Remote Unauthenticated API Access   author: JC   severity: critical   reference:     – https://nvd.nist.gov/vuln/detail/CVE-2023-35078   description: Identifies vulnerable instances of Ivanti Endpoint Manager Mobile (EPMM), formerly MobileIron Core, through 11.10 allows remote attackers to obtain PII, add an administrative account, and change the configuration because of an authentication bypass.   tags: ivanti, mobileiron, epmm, auth-bypass   requests:   – method: GET     path:       – “{{RootURL}}/mifs/aad/api/v2/ping”       matchers-condition: and     matchers:                           – type: status         status:           – 200               – type: word         part: body         words:           – “vspVersion”           – “apiVersion”         condition: and

CISA recommends administrators use the following CISA-developed nuclei template to determine vulnerability to CVE-2023-35081:

id: CVE-2023-35081   info:   name: Ivanti EPMM Remote Arbitrary File Write   author: JC   severity: High   reference:     – https://nvd.nist.gov/vuln/detail/CVE-2023-35081   description: Identifies vulnerable unpatched versions of Ivanti Endpoint Manager Mobile (EPMM), formerly MobileIron Core, through 11.10.0.3, 11.9.1.2, and 11.8.1.2 that allows an authenticated administrator to perform arbitrary file writes to the EPMM server.   tags: ivanti, mobileiron, epmm   requests:   – method: GET     path:       – “{{RootURL}}/mifs/c/windows/api/v2/device/registration”       matchers-condition: and     matchers:                           – type: status         status:           – 200               – type: regex         part: all         regex:           – ‘.*?VSP ((0?[0-9]|10)(.d+){1,3}|11.(0?[0-7])(.d+){1,2}|11.8.0(.d+)?|11.8.1.[0-1]|11.9.0(.d+)?|11.9.1.[0-1]|11.10.0.[0-2]).*’

Run the following NCSC-NO-created checks to check for signs of compromise:

1. Investigate logs in centralized logging solutions or forwarded syslogs from EPMM devices for any occurrences of /mifs/aad/api/v2/.
2. Look for spikes or an increase of EventCode=1644 in the AD since at least April 2023. The LDAP queries performed by EPMM when the threat actor used the MIFS API generated tens of millions of this event code. Also look for EventCodes 4662, 5136, and 1153.
3. To detect tunneling activity through Sentry, look for traffic from EPMM devices to other internal servers, as well as TLS traffic towards instances of EPMM with different TLS certificates than the instance itself would possess. Traffic to EPMM with certificates originating from endpoints further inside the network, e.g. standard Windows generated certificates such as CN=EXCHANGE01 or similar.
4. Perform forensic analysis of disk and memory since log retention may be poor and threat actors have been observed deleting log entries. Pay particular attention to unallocated disk space (free space on filesystem).
5. Check for activity from ASUS routers in your own country towards EPMM and Sentry devices.

INCIDENT RESPONSE

If compromise is detected, organizations should:

1. Quarantine or take offline potentially affected hosts.
2. Reimage compromised hosts.
3. Provision new account credentials.
4. Collect and review artifacts such as running processes/services, unusual authentications, and recent network connections.
5. Report the compromise to CISA via CISA’s 24/7 Operations Center (report@cisa.gov or 888-282-0870) or to NCSC-NO via NCSC-NO’s 24/7 Operations Center (cert@ncsc.no or +47 23 31 07 50).

MITIGATIONS

CISA and NCSC-NO recommend organizations:

• Upgrade Ivanti EPMM versions to the latest version as soon as possible. See Ivanti CVE-2023-35081 – Remote Arbitrary File Write for patch information. This patch protects against CVE-2023-35078 and CVE-2023-35081.
  • See the Evidence of Vulnerability Methods section of this advisory for CISA-developed nuclei templates to find any EPMM versions vulnerable to CVE-2023-35078 and CVE-2023-35081.
  • Organizations using unsupported versions (i.e., versions prior to 11.8.1.0) should immediately upgrade to a supported version. If you cannot immediately upgrade, apply the Ivanti-provided RPM fix for CVE-35078 (this workaround does not protect against CVE-2023-35081):
    • Login to command line shell (CLI) in enable mode.
    • Run the following command: # install rpm url https://support.mobileiron.com/ivanti-updates/ivanti-security-update-1.0.0-1.noarch.rp
    • See Ivanti’s Knowledge Base (KB) Remote unauthenticated API access vulnerability – CVE-2023-35078 for more information on the RPM fix.
• Treat MDM systems as high-value assets (HVAs) with additional restrictions and monitoring. MDM systems provide elevated access to thousands of hosts and should be treated as high value assets (HVAs) with additional restrictions and monitoring.
• Follow best cybersecurity practices in production and enterprise environments, including mandating phishing-resistant multifactor authentication (MFA) for all staff and services. For additional best practices, see CISA’s Cross-Sector Cybersecurity Performance Goals (CPGs). The CPGs, developed by CISA and the National Institute of Standards and Technology (NIST), are a prioritized subset of IT and OT security practices that can meaningfully reduce the likelihood and impact of known cyber risks and common TTPs. Because the CPGs are a subset of best practices, CISA and NCSC-NO also recommend software manufacturers implement a comprehensive information security program based on a recognized framework, such as the NIST Cybersecurity Framework (CSF).

VALIDATE SECURITY CONTROLS

In addition to applying mitigations, CISA and NCSC-NO recommends exercising, testing, and validating your organization’s security program against the threat behaviors mapped to the MITRE ATT&CK for Enterprise framework in this advisory. CISA recommends testing your existing security controls inventory to assess how they perform against the ATT&CK techniques described in this advisory.

To get started: 

1. Select an ATT&CK technique described in this advisory (see Table 1–Table 7).
2. Align your security technologies against the technique.
3. Test your technologies against the technique.
4. Analyze your detection and prevention technologies’ performance.
5. Repeat the process for all security technologies to obtain a set of comprehensive performance data.
6. Tune your security program, including people, processes, and technologies, based on the data generated by this process.

CISA recommends continually testing your security program, at scale, in a production environment to ensure optimal performance against the MITRE ATT&CK techniques identified in this advisory.

REFERENCES

[1] Ivanti: CVE-2023-35078 – Remote Unauthenticated API Access Vulnerability

[2] Ivanti: CVE-2023-35081 – Remote Arbitrary File Write

[3] CISA: Potential for China Cyber Response to Heightened U.S.-China Tensions

[4] CISA: Top Routinely Exploited Vulnerabilities

ACKNOWLEDGEMENTS

Ivanti contributed to this joint advisory.

VERSION HISTORY

August 1, 2023: Initial version.

APPENDIX: INDICATORS OF COMPROMISE

NCSC-NO observed the following webshell hash:

c0b42bbd06d6e25dfe8faebd735944714b421388

NCSC-NO observed the following hash of mi.war:

1cd358d28b626b7a23b9fd4944e29077c265db46

NCSC-NO observed the following JA3 Hashes used against MobileIron Core:

2d5bd942ebf308df61e1572861d146f6 473cd7cb9faa642487833865d516e578 579ccef312d18482fc42e2b822ca2430 849d3331f3e07a0797a02f12a6a82aa9 8d9f7747675e24454cd9b7ed35c58707 ad55557b7cbd735c2627f7ebb3b3d493 cd08e31494f9531f560d64c695473da9 e1d8b04eeb8ef3954ec4f49267a783ef e60dc8370ecf78cf115162fbc257baf5 e669667efb41c36f714c309243f41ca7 e84a32d43db750b206cb6beed08281d0 eb5fdc72f0a76657dc6ea233190c4e1c

NCSC-NO observed the following JA3 Hashes used against Exchange when tunneling via EPMM Sentry:

0092ce298a1d451fbe93dc4237053a96 00e872019b976e69a874ee7433038754 01ecd9ab9be75e832c83c082be3bdf18 0212a88c7ed149febdefa347c610b248 02be3b93640437dbba47cc7ed5ab7895 03f8852448a85e14f2b4362194160c32 045f8ccdac6d4e769b30da406808da71 04e7f5787f89a597001b50a37b9f8078 070f9fe9f0ec69e6b8791d280fde6a48 07a624d7236cca3934cf1f8e44b74b52 09df72c01a1a0ad193e2fff8e454c9c4 0b28842d64a344c287e6165647f3b3fe 0b8e1211de50d244b89e6c1b366d3ccf 0cb0380cf75a863b3e40a0955b1ada9f 0da24834056873a8cd8311000088e8be 0e1fad8ffaa7a939f0a6cbf9cd7e2fcd 0f6e78839398c245d13f696a3216d840 119f8c9050d1499b6f958b857868b8ce 11c506d5e3fb7e119c4287202c96a930 1336df27f94b25a25acac9db3e61e461 14671c3f8deca7d73a03b74cb854c21d 146caf9bd0153428f54e9ef472154983 14994353f3ea6fd25952a8c7d57f9ecf 151bc875df15d1385e6eb02f9edaba06 15a074a397727b26a846b443b99c20ff 1660f3d882a4311ca013ee4586e01fd9 16a74fc216f8a4ce43466bb83b6d3fd2 188623fdd056c4ed13d1ff34c7377637 19f51486abd40c9f0fc0503559a6c523 1a024e63721c610d2e54e67d62cd5460 1aa7dae8f2ae0a29402ed51819f82db4 1abfdeaadb74a0f7c461e7bab157b17f 1b6720ed0b67c910a80722ce973d6217 1b7d9368c6ce7623fdbc43f013626535 1e0850e10a00c9bbdd5c582ff4cb6833 1ec71612e438cf902913eec993475eb9 206fed3a39d9215c35395663f5bb3307 22cc1b3bc9f99d3a520ae58fee79a0d5 23e3e6fa8b23d9bc19e82de4e64c79e9 253fd4659bf21be116858bc0f206c5b9 276e175d4fe8454c4c47e966d8cb3fa3 289a450c7478dd52a10c6ed2fb47f7e9 2aa8ba7478b1362274666d714df575bc 2beecb6b9e386f29d568229a9953c3d2 2ebc7fdceaa9a0df556e989d77157006 3003024afe64b4e8a5a30825c14bbb12 3082e669dda9d023e2dcd8b9549a84a8 309d33c6f77a3fc75654c44c61596ccd 30a9f568eb3df79352fc587a078623b6 30be84e6b95f44c203f8e7fce7339a8e 3268a5097a543c7dbd82c39a9193b7fe 32775ead3ea1ad7db2f4bea67fe0cabb 34ac9a6ef5d285119abec50fbe41fcfe 34d92552e278710c1e84f0bd8dc3a6b8 361f47a6357cc6e3a9bcdd20cfaaf0e9 3685abc75517e61e47e52e5f2d060f54 3744004013135b9f9a05cb58cda8134d 37d952966ea7e79277803f13d7147544 391a4c2c7541b8b78e2f99bf586e9794 393662e5aa0cb49c5d666a6d10a1ade6 3962b622c5aa815afb803b92aa948424 3b22af324abded2781ed8f6a61f3654f 3b30b4555cc8b4b164ad03cf322cbea8 3bd1bdb5e90b9590a8878bff2ada8204 3be529eb3a7daaf34f963a22188f6139 3dd13faad1c45eb0c23e4567210f7eac 403273b51f91cf3c333695e5532cb2c3 404f56045e436d53ead2177bf957ba39 41854adbc73b0b58e5c566f60bb0df25 43c22dabb1e6d2449a39c2f7e974d537 476e72bbda5b78d188766139889e3038 4898a51256ae7d914a5ffd5695973470 49230c486f0fd383cd301fe162d6a786 4959a611b9885022d81b4bc8e4b1d149 495c6ff7ca0379ad0891bac47917d09a 49d2bd08038dc7dada221008591940f9 4c1b73ec52e6eec0c5d20577fcbc9ef1 4d34db639ba84b11822fb3dac47ed7d1 5244b163f9326a1e5eaa8860f7543f99 539f1a5183800a96228458932f9307f7 5466368d4659f1b1470bcb09e65b484d 549cde6535a884126755fc53f59a820c 555389e92c622b87d3fc395fd8723501 588d0b42e54174a98e1eca59945e8b32 58bc21d305a65c41745327f142f3ac12 59401c9a60449c742d073d93d1b7039a 59eec218522cc5c7743a0d37892a3345 59faf75430e9326d3ae9d231bb3ae8c6 5d0259ca16cfc2d7d1b0fac69f29ab05 5d55026fb84dba91ac01e2095504b1bc 5e35f50c692081fd6c7ddac1272e2d6c 5f4d5965af741bba59b7c8d3425f33dd 6010282004917ecf3900babf61456432 6088c2a04c94cdcd5a283a6d1622ffba 61dee38d2f97220efb1218ad8971e3ab 62ac194f2526eb45485526bca35c8f43 634296a023280d020674c873d0199760 635755dadfab8b92fb502aafb09122db 63fc58be0d7b48eaa34da7f752ae8ae6 6441640409815cfb4bf469e685e1bdb5 646973d1928c401ba80961c12cbf84a2 65eef0a0ee257254ef0418aa57192cfb 66f6a192083a7ab00ae8e0b5cc52e8f4 67a42e2e27ffc26d1f3d0ceb8384afd0 689385f1218e0d4c347595648ca6a776 692f91c0c5e9e93e0a24bd3392887ca1 69ecf52960c8bd9e746dfe9ee19c11f6 6e359f3bbc622e9b1ed36f6e3d521bcf 6e3650528f719fc50988a1f697644832 6ead0d5d3f87911c27f3ae0a75e6b5bc 6f1fa8b444caf0d8238f948279ca74e1 6fb8cdf567dd7d89d53b5771d769cb5f 706b6055658aff067ae370f23831ef6b 708140c311d3d69418f75c928e7535a0 719ec5da8f2153a436ee8567ff609894 7292ef4cdca529071fad97496e1c9439 74871691eac48156ce0da2cfa3ab401a 74cf24f2a66a31c88b6fcfe01f12160c 75e874d8e0a79697633b87ea5e798b1c 76c0d09fed2f33babb0de8ee2c07144c 77a01363fa2b29af25c004da9570e23c 78988c65e9b70e7929e747408d8f0b0e 79c6d12d168b85437384b20eb94e106b 7b4137b4e85f31a81bb5bafeda993947 7b9db1d58326c1fa276ba2a39bcc2617 7cbc7459db5327c26476549f225030f5 7cd727171c2522f51417edeeba4f1791 7e3630c67c802eabb67b108ad4d7ded7 802f5d34c230da40c0912a1c5a9b702b 80bd0f3610f6c4d60584a5be0b8a3016 819030799f0020ed724c2ef3ffaa56c6 8207129585da68066ed08e94216d76ee 821f649d08687e22f96cea99fbb5d3a3 830838cb0620d659405a74401cd72557 833d3201066f5184c874c73a2083c448 840f488b7c0a5d686d1e89908735f354 84301b967a4d9a242466c04901bad691 85c3fac6a9885362c448f434671e362f 883b9fe16e45c388968defc73a5fba7a 8a6b0ba3496eeca39d6d3f9bae830c90 8ad0fd4b78c89bd63b97343fda1eeccb 8b0ae9029974091df12210255aaecad6 8b297f8b219e968932293ee7a8242ca3 8bb1781e756a53cd00d9b2ec670fa21e 8d5515351afdf27b013f96a05bf45147 8fafa73e9985e05d0c1c964da770c567 905967b08bd44cfa60d969229921ac23 9188ef45ea917a91ec9b92b5dd8cd90d 918dfab0333ae15d61f14fd24b5eaaac 922a3272aad17c9eaad733696a4321da 9253399537fad8448f1d4732dd79f6fa 934a8a6528e91caa019acb76e791a71d 95588e0386206fa02912cfcaf18c1220 9610328cdaa4694800c2c93410f8ce82 9622902cc43f4a20d0d686a37e4d8232 96c41e4c4a1812187fb279b9299ad63b 984c4653a563b19c87f264611a6adc01 9980febfaf901d4113a1c473f79d7eb6 9a176d818edff838fc057cea3ee372c0 9ba21c5148913186a5bf877078cbc048 9cfda02ef7e04c469b77f8197a249c17 9d74d395bd2f72a47a5c980e6040df5a 9df128ebe0c82064aa746647883112c9 9e5613533972a9d42d2e3344a4e58566 9ec17429eed5446e3720796ab50d8c60 9f2438aaab4744c4b7b5b7287a783099 9f3bf94572344b36f6ef1689cb30c66e 9fdd7a85b3a4ef8ded73beb3e6218109 a1b732a9af792f75a68ed78d72ffb8f6 a260d836428cdb971bdf147ca6940160 a4f11b1eb659869a0ae70898a4a0e5ee a596ebbcf438980c880d711315e4fdf1 a80b6a354b493264f37aa39d0d41b5fc a89df6156eb5a2de196388d4a123b470 a96837fe533247abb7f88000d0216a50 a98cf0a359f430a00f4f3d522f5b6cc0 aa2fe3a253e169b05e1782ca57a688d2 aef0172a2c03f77912de0bbf14aee00f af06c3e72f2f307515ba549174d8e5a6 b311ab82b30f41b12cb9089d00c4a1ff b4f31423445b5f13675f205ac997f41f b50666c9aed1c2f222c56b6e9b326d27 b53f179b3f25f72bb0c7ccf45bf8beee b57f3e41c03803306b0ee2111f7ef823 b79434613820faf30d58f103c4415a29 b8366aaa5ed51c0dea3fc90ef7e14889 b8f6b0d234a305c25411e83fd430c624 b956ed2b848dabb4e79ab7358233861b b9ecb08402df0f1f6e1ce76b8ad6e91f ba4a616c8d4ab9358a82b321d8e618bf bcd62f3e029f96f62c24d50d2d1402ac bcf75736d176394f3df69f3e0ef7dd9f be1f24457141d80206bc2e58f55dc879 c013f308d170aa2eca4a5b0f0bbd3ccb c0a2fd066c955137036f92da2c3a3ff1 c17b3ec40ed5216e44311138aafaea2c c262a39f49604f05a5656213f758cd46 c66f36eb180438882133717c3abb5157 c986c7bf720ce1463c3d628d2b3dad01 c9c16287cbbe5a037244e374ba84aecc cbcd728a2350712b5747cd3447473deb cbeeb123efe8cf7f842426b673415c28 ccb15eef4287c8efa472915bcb4ec458 ccdddb69e9344a039c4ac9c49a6f2d7b cd1312be032256a10cf866af3e9afae9 ce0dd163d9e02bfd42d61024523cb134 ceef2e728db1b5ae15432f844eeb66e1 d12d98a0877f6e3c8b5a59f41cc4de9b d131f17689f1f585e9bfdcdb72a626bb d173076d97a0400a56c81089912b9218 d255291bb8e460626cb906ebacc670e5 d2cea317778ad6412c458a8a33b964fd d3cfee76468a9556fd9d017c1c8ee028 d3d72f4c7038f7313ad0570e16c293bf d485a1b5db2f97dc56500376d677aa89 d662d20507bebc37b99a4d413afa2752 d711d577b9943ab4e2f8a2e06bb963e3 d92e87d2689957765987e2be732d728e d966c6c822122e96f6e9f5f1d4778391 daee31d7cc6e08ead6afad2175989e1d dbb293176747fa1c2e03cbc09433f236 dc26ef761c7ec40591b1fe6e561b521d dc9e6edeb7557bc80be68be15cebb77a dddfbae77336120febd5ad690af3e341 e1f579227327ebb21cde3f9e7511db01 e3c642432a815a07f035e01308aaa8fc e54329351788661f2a8d4677a759fc42 e82b7ad2c05f4617efbc86a78c1e61e9 e99cffa2afa064625f09e1c5aca8f961 ea6bd3db104ca210b5ad947d46134aaf eb277d809a59d39d02605c0edd9333e9 ed82a50d98700179c8ae70429457477a ef35374f4146b3532f0902d6f7f0ef8c ef4c4d79f02ac404f47513d3a73e20c7 f05a5a60ad6f92d6f28fa4f13ded952f f0776dfe17867709fdb0e0183ed71698 f20fbfd508e24d50522eadf0186b03eb f3d751b0585855077b46dfce226cfea1 f4dd9bb28d680a3368136fb3755e7ea9 f804388f302af1f999e4664543c885a1 f8bcc8f99a3afde66d7f5afb5d8f1b43 f8d6f89aecf792e844e72015c9f27c95 f967460f8c6de1cedb180c90c98bfe98 f9d5cc0cbae77ea1a371131f62662b6b fa4f1a3b215888bc5f19b9f91ba37519 fdff2bf247a7dad40bac228853d5a661 fe6e7fac4f0b4f25d215e28ca8a22957 fe9de1cdd645971c5d15ee1873c3ff8d febba89b4b9a9649b3a3bf41c4c7d853

NCSC-NO observed the following user agents communicating with Exchange (OWA and EWS):

Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:109.0) Gecko/20100101 Firefox/114.0 Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/92.0.4515.131 Safari/537.36 Edg/92.0.902.67

NCSC-NO observed the following user agents communicating with Exchange webshell:

Mozilla/5.0 (iPhone; U; CPU iPhone OS 4_0_1 like Mac OS X; en-us) AppleWebKit/532.9 (KHTML, like Gecko) Version/4.0.5 Mobile/8A306 Safari/6531.22.7 Mozilla/5.0 (Macintosh; U; Intel Mac OS X; en-US; rv:1.8.0.7) Gecko/20060909 Firefox/1.5.0.7 Mozilla/5.0 (Linux; Android 7.0; Moto C Build/NRD90M.059) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Mobile Safari/537.36 Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.02272.101 Safari/537.36 Mozilla/5.0 (Linux; Android 5.1.1; SAMSUNG SM-J120M Build/LMY47X) AppleWebKit/537.36 (KHTML, Like Gecko) SamsungBrowser/6.4 Chrome/56.0.2924.87 Mobile Safari/537.36 Mozilla/5.0 (iPhone; CPU iPhone OS 9_0_2 like Mac OS X) AppleWebKit/601.1.45 (KHTML, like Gecko) Version/9.0 Mobile/13A452 Safari/601.1

NCSC-NO observed the following user agents communicating with Exchange Autodiscover:

ExchangeServicesClient/15.00.0913.015 Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/92.0.4515.131 Safari/537.36 Edg/92.0.902.67 Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Firefox/114.0 Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML  like Gecko) Chrome/114.0.0.0 Safari/537.36 Edg/114.0.0.0

NCSC-NO observed the following user agents communicating with EWS (/ews/Exchange.asmx):

Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/103.0.5060.114 Safari/537.36 Edg/103.0.1264.49 Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/92.0.4515.131 Safari/537.36 Edg/92.0.902.67

NCSC-NO observed the following user agent communicating with Exchange (/powershell):

Windows WinRM Client

 

 

This post was originally published on this site

SUMMARY

The Australian Signals Directorate’s Australian Cyber Security Centre (ACSC), U.S. Cybersecurity and Infrastructure Security Agency (CISA), and U.S. National Security Agency (NSA) are releasing this joint Cybersecurity Advisory to warn vendors, designers, and developers of web applications and organizations using web applications about insecure direct object reference (IDOR) vulnerabilities. IDOR vulnerabilities are access control vulnerabilities enabling malicious actors to modify or delete data or access sensitive data by issuing requests to a website or a web application programming interface (API) specifying the user identifier of other, valid users. These requests succeed where there is a failure to perform adequate authentication and authorization checks.

These vulnerabilities are frequently exploited by malicious actors in data breach incidents because they are common, hard to prevent outside the development process, and can be abused at scale. IDOR vulnerabilities have resulted in the compromise of personal, financial, and health information of millions of users and consumers.

ACSC, CISA, and NSA strongly encourage vendors, designers, developers, and end-user organizations to implement the recommendations found within the Mitigations section of this advisory—including the following—to reduce prevalence of IDOR flaws and protect sensitive data in their systems.

• Vendors, designers, and developers of web application frameworks and web applications: Implement secure-by-design and -default principles and ensure software performs authentication and authorization checks for every request that modifies, deletes, and accesses sensitive data.
  • Use automated tools for code review to identify and remediate IDOR and other vulnerabilities.
  • Use indirect reference maps, ensuring that IDs, names, and keys are not exposed in URLs. Replace them with cryptographically strong, random values—specifically use a universally unique identifier (UUID) or a globally unique identifier (GUID).
  • Exercise due diligence when selecting third-party libraries or frameworks to incorporate into your application and keep all third-party frameworks and dependencies up to date.
• All end-user organizations, including organizations with software-as-a-service (SaaS) models:
  • Use due diligence when selecting web applications. Follow best practices for supply chain risk management and only source from reputable vendors.
  • Apply software patches for web applications as soon as possible.
• End-user organizations deploying on-premises software, infrastructure-as-a-service (IaaS), or private cloud models:
  • Review the available authentication and authorization checks in web applications that enable modification of data, deletion of data, or access to sensitive data.
  • Conduct regular, proactive vulnerability scanning and penetration testing to help ensure internet-facing web applications and network boundaries are secure.

Download the PDF version of this report:

TECHNICAL DETAILS

Description

IDOR vulnerabilities are access control vulnerabilities in web applications (and mobile phone applications [apps] using affected web API) that occur when the application or API uses an identifier (e.g., ID number, name, or key) to directly access an object (e.g., a database record) but does not properly check the authentication or authorization of the user submitting the request. Depending on the type of IDOR vulnerability, malicious actors can access sensitive data, modify or delete objects, or access functions.

• Horizontal IDOR vulnerabilities occur when a user can access data that they should not be able to access at the same privilege level (e.g., other user’s data).
• Vertical IDOR vulnerabilities occur when a user can access data that they should not be able to access because the data requires a higher privilege level.
• Object-level IDOR vulnerabilities occur when a user can modify or delete an object that they should not be able to modify or delete.
• Function-level IDOR vulnerabilities occur when a user can access a function or action that they should not be able to access.

Typically, these vulnerabilities exist because an object identifier is exposed, passed externally, or easily guessed—allowing any user to use or modify the identifier.

• In body manipulation, an actor modifies the HTML form field data in the body of a POST request to impact targeted records.
• In URL tampering, an actor modifies an identifier in URLs to impact targeted records.
• In cookie ID manipulation, the actor modifies an identifier in a cookie to an identifier of a different user (including administrative users) in an attempt to gain access to that account.
• In HTTP/JSON request tampering, an actor uses a web proxy to intercept and alter arbitrary portions of legitimate requests, including values inside JSON objects.

Impact

These vulnerabilities are common[1] and hard to prevent outside the development process since each use case is unique and cannot be mitigated with a simple library or security function. Additionally, malicious actors can detect and exploit them at scale using automated tools. These factors place end-user organizations at risk of data leaks (where information is unintentionally exposed) or large-scale data breaches (where a malicious actor obtains exposed sensitive information). Data leaks or breaches facilitated by IDOR vulnerabilities include:

• An October 2021 global data leak incident where mobile phone data, including text messages, call records, photos, and geolocation from hundreds of thousands of devices was exposed by insecure “stalkerware” apps.[2] The apps collected and relayed data from the phones to the same foreign server infrastructure, which contained an IDOR vulnerability, CVE-2022-0732.[3] This led to exposure of the collected app data.[4]
• A 2019 data breach incident where more than 800 million personal financial files, including bank statements, bank account numbers, and mortgage payment documents, from a U.S. Financial Services Sector organization were exposed.[5],[6]
• A 2012 data breach incident where a malicious cyber actor obtained the personal data of more than 100,000 mobile device owners from a U.S. Communications Sector organization’s publicly accessible website.[7]

MITIGATIONS

Vendors and Developers

ACSC, CISA, and NSA recommend that vendors, designers, and implementors of web applications—including organizations that build and deploy software (such as HR tools) for their internal use and organizations that create open-source projects—implement the following mitigations. These mitigations may reduce prevalence of IDOR vulnerabilities in software and help ensure products are secure-by-design and -default.

• Implement and inject secure-by-design and -default principles and best practices into each stage of the software development life cycle (SDLC). Particular recommended practices are defined in the National Institute of Security and Technology’s (NIST’s) Secure Software Development Framework (SSDF), SP 800-218. Lend special attention to:
  • Conducting code reviews [SSDF PW 7.2, RV 1.2] against peer coding standards, checking for backdoors, malicious content, or logic flaws.
    • ACSC, CISA, and NSA recommend using automated code analysis tools for all supported releases to identify and remediate vulnerabilities.
  • Following secure coding practices [SSDF PW 5.1] for web and mobile applications to ensure that they properly validate user input and generate strong user IDs.
    • Use indirect reference maps, such that IDs, names, and keys are not exposed in URLs. Replace them with cryptographically strong, random values—specifically use a UUID or a GUID. Note: UUIDs and GUIDs should not be used for security capabilities. See Request for Comment (RFC) 4122 for more information.
    • Configure applications to deny access by default and ensure the application performs authentication and authorization checks for every request to modify data, delete data, and access sensitive data. For example:
      • Normalize requests. There are many ways to encode and decode web inputs. Decode and normalize inputs before creating access control checkpoints. Ensure the access control system and other parts of the web application perform the same normalization.
      • Implement parameter verification leveraging syntactic and logical validation, such that web applications validate all inputs received with every HTTP/S request. Denying invalid requests can reduce the burden on the access control system.
        • Syntactic validation verifies that for each input the incoming value meets your applications’ expectations. When doing syntactic validation, verify that strings are within the minimum and maximum length required, strings do not contain unacceptable characters, numeric values are within the minimum and maximum boundaries, and the input is of the proper data type.
        • Logical validation adds checks to see if the input values make sense and are consistent with design intent. When doing logical validation, verify authorization checks are performed in the correct locations, are of varying pedigree, and that there is error handling of failed authentication and authorization requests.
    • Use CAPTCHA to limit automated invalid user requests where feasible.
    • Use memory-safe programming languages where possible.
  • Testing code to identify vulnerabilities and verify compliance with security requirements [SSDF PW 8.2].
  • Use automated testing tools to facilitate testing, fuzz testing tools to find issues with input handling,[8] and penetration testing to simulate how a threat actor may exploit the software. Consider using dynamic application security testing (DAST) tools to identify IDOR vulnerabilities in web applications.
  • Conducting role-based training [SSDF PO 2.2] for personnel responsible for secure software development.
  • Exercising due diligence when selecting third-party libraries or frameworks to incorporate into your application [SSDF PW 4.1].
    • Review and evaluate third-party components in the context of their expected use.
    • Verify the integrity of the product through hash or signature verification.
    • If provided, review component’s Software Bill of Materials (SBOM) for outdated, vulnerable, or unauthorized applications before using it.
    • Keep all third-party frameworks and dependencies up to date to limit vulnerability inheritance. Note: Organizations should maintain an inventory or catalog of third-party frameworks and dependencies to assist with proactive updates. Consider using tools to identify project dependencies and known vulnerabilities in third-party code. See OWASP’s Top Ten Proactive Controls 2018, C2: Leverage Security Frameworks and Libraries, for more information.

      For more information, see the joint Enduring Security Framework’s Securing the Software Supply Chain: Recommended Practices Guide for Developers, CISA’s Supply Chain Risk Management Essentials, and ACSC’s Cyber Supply Chain Risk Management.

• Establish a vulnerability disclosure program to verify and resolve security vulnerabilities disclosed by people who may be internal or external to the organization.

Additionally, ACSC, CISA, and NSA recommend following cybersecurity best practices in production and enterprise environments. Software developers are high-value targets because their customers deploy software on their own trusted networks. For best practices, see:

• ACSC’s Essential Eight. The Essential Eight are prioritized strategies to help cybersecurity professionals mitigate cybersecurity incidents caused by various cyber threats.
• CISA’s Cross-Sector Cybersecurity Performance Goals (CPGs). The CPGs, developed by CISA and NIST, are a prioritized subset of IT and OT security practices that can meaningfully reduce the likelihood and impact of known cyber risks and common tactics, techniques, and procedures. Because the CPGs are a subset of best practices, ACSC, CISA, and NSA also recommend software manufacturers implement a comprehensive information security program based on a recognized framework, such as the NIST Cybersecurity Framework (CSF).
• NSA’s Top Ten Cybersecurity Mitigations. The Top Ten sets priorities for enterprise activities to counter a broad range of exploitation techniques and minimize mission impact.

All End-User Organizations

ACSC, CISA, and NSA recommend that all end-user organizations, including those with on-premises software, SaaS, IaaS, and private cloud models, implement the mitigations below to improve their cybersecurity posture.

• Exercise due diligence when selecting web applications. Follow best practices for supply chain risk management and source from reputable vendors that demonstrate commitment to secure-by-design and -default principles.
  • Verify the integrity of the product through hash or signature verification.
  • If provided, review the SBOM for outdated, vulnerable, or unauthorized applications before using the product.

    For more information, see the Enduring Security Framework’s Securing the Software Supply Chain: Recommended Practices Guide for Customers, CISA’s Supply Chain Risk Management Essentials, and ACSC’s Cyber Supply Chain Risk Management.

• Apply software patches for web applications as soon as possible.
• Configure the application to log and generate alerts from tamper attempts—with this information, network defenders can investigate and take appropriate follow-on actions.
  • Establish a baseline to efficiently identify abnormal behavior. Note: Web application error codes such as HTTP 404 and HTTP 403 are associated with common enumeration techniques.
  • Aggregate logs into a centralized solution (e.g., a security information and event management [SIEM] tool) to facilitate active monitoring and threat hunting.
• Create, maintain, and exercise a basic cyber incident response plan (IRP) and associated communications plan. Plans should include response and notification procedures for data breach and cyber incidents. For more information, see:
  • ACSC: Preparing for and Responding to Cyber Incidents
  • ACSC: Cyber Incident Response Plan – Guidance
  • ACSC: Cyber Incident Response Readiness Checklist
  • Office of the Australian Information Commissioner (OAIC): Data Breach Preparation and Response
  • OIAC: Data Breach Response Plan
  • CISA: Incident Response Plan Basics
  • CISA: Federal Government Cybersecurity Incident and Vulnerability Response Playbook (Although tailored to U.S. Federal Civilian Branch (FCEB) agencies, these playbooks provide operational procedures for planning and conducting cybersecurity incident and vulnerability response activities and detail steps for both incident and vulnerability response.)
  • CISA: Protecting Sensitive and Personal Information from Ransomware-Caused Data Breaches

Additionally, ACSC, CISA, and NSA recommend following cybersecurity practices. For best practices, see ACSC’s Essential Eight, CISA’s CPGs, and NSA’s Top Ten Cybersecurity Mitigation Strategies.

End-User Organizations with On-Premises Software, IaaS, or Private Cloud Models

ACSC, CISA, and NSA recommend that organizations:

• Conduct regular, proactive penetration testing to ensure network boundaries, as well as web applications, are secure. Prioritize web applications that are internet-facing and contain user login functionality. Such testing may be beyond the technical or financial capabilities of some organizations. Consider using a trusted third party for penetration testing to discover new attack vectors (notably prior to deployment of new or altered internet-facing services). Note: Organizations should consult with their legal counsel as appropriate to determine which systems and applications can be included in the scope of the penetration testing.
  • Use web application penetration testing tools to capture the user identifier sent to the web server when requesting a web page containing sensitive data and map all locations where user input is used to reference objects directly. Test with users of various privilege levels (e.g., a normal user and admin user).
• Use DAST and other vulnerability scanners to detect IDOR vulnerabilities. DAST tools identify vulnerabilities in web applications with penetration tests and generate automated alerts. Note: Exercise due diligence when selecting DAST tools. Not all DAST tools can detect IDOR vulnerabilities—tools with the ability may need the environment configured in a specific way and may also need custom rules in place. Sufficient DAST tools often ingest the application API documentation to build a model of the application. While these tools can be used to detect IDOR vulnerabilities, they are not foolproof and should be used with other security testing methods to ensure comprehensive coverage.
• Immediately report detected vulnerabilities to the vendor or developer. Alternatively (or if the vendor or developer fails to respond), report the vulnerability to CISA at cisa.gov/report.
• Consider establishing a vulnerability disclosure program to verify, resolve, and report security vulnerabilities disclosed by people who may be internal or external to the organization.
• Use a web application firewall (WAF) to filter, monitor, and block malicious HTTP/S traffic traveling to the web application.
• Use a data loss prevention (DLP) tool to prevent unauthorized data from leaving the application.

ACSC, CISA, and NSA recommend that organizations with on-premises software or IaaS consider using SaaS models for their internet-facing websites.

End-User Organizations with SaaS Models

Organizations leveraging SaaS with sufficient resources may consider conducting penetration testing and using vulnerability scanners. However, such tests may interfere with service provider operations. Organizations should consult with their legal counsel as appropriate to determine what can be included in the scope of the penetration testing.

INCIDENT RESPONSE

If you or your organization are victim to a data breach or cyber incident, follow relevant cyber incident response and communications plans, as appropriate.

• Australia: Australian organizations that have been impacted or require assistance in regards to a cybersecurity incident can contact ACSC via 1300 CYBER1 (1300 292 371), or by submitting a report to cyber.gov.au.
• United States: U.S. organizations may report cybersecurity incidents to CISA’s 24/7 Operations Center at Report@cisa.dhs.gov, cisa.gov/report, or (888) 282-0870. When available, please include the information regarding the incident: date, time, and location of the incident; type of activity; number of people affected; type of equipment used for the activity; the name of the submitting company or organization; and a designated point of contact.

RESOURCES

• For additional guidance on designing secure-by-design and -default products, see joint guide Shifting the Balance of Cybersecurity Risk: Principles and Approaches for Security-by-Design and -Default.
• For additional guidance on protecting against data breaches, see ACSC’s webpage on data breaches.

REFERENCES

[1] A01 Broken Access Control – OWASP Top 10:2021

[2] A massive ‘stalkerware’ leak puts the phone data of thousands at risk

[3] Mobile device monitoring services do not authenticate API requests

[4] Behind the stalkerware network spilling the private phone data of hundreds of thousands

[5] First American Financial Corp. Leaked Hundreds of Millions of Title Insurance Records

[6] Biggest Data Breaches in US History [Updated 2023]

[7] AT&T Hacker ‘Weev’ Sentenced to 3.5 Years in Prison

[8] Fuzzing | OWASP Foundation

DISCLAIMER

The information in this report is being provided “as is” for informational purposes only. ACSC, CISA, and NSA do not endorse any commercial product or service, including any subjects of analysis. Any reference to specific commercial products, processes, or services by service mark, trademark, manufacturer, or otherwise, does not constitute or imply its endorsement, recommendation, or favoring by the United States or Australian Governments, and this guidance shall not be used for advertising or product endorsement purposes.

PURPOSE

This document was developed in furtherance of the authors’ cybersecurity missions, including their responsibilities to identify and disseminate threats, and to develop and issue cybersecurity specifications and mitigations. This information may be shared broadly to reach all appropriate stakeholders.