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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2021.3354 BIG-IP tmsh vulnerability CVE-2020-5858 8 October 2021 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: BIG-IP modules BIG-IQ Publisher: F5 Networks Operating System: Network Appliance Impact/Access: Execute Arbitrary Code/Commands -- Existing Account Resolution: Patch/Upgrade CVE Names: CVE-2020-5858 Original Bulletin: https://support.f5.com/csp/article/K36814487 Comment: The original publication date for this advisory was Mar 27, 2020. F5 updated the advisory on Oct 06, 2021. - --------------------------BEGIN INCLUDED TEXT-------------------- K36814487: BIG-IP tmsh vulnerability CVE-2020-5858 Original Publication Date: 27 Mar, 2020 Latest Publication Date: 06 Oct, 2021 Security Advisory Description Users with non-administrator roles (for example, Guest or Resource Administrator) with TMOS Shell (tmsh) access can run arbitrary commands with elevated privilege using a crafted tmsh command. (CVE-2020-5858) Impact BIG-IP and BIG-IQ This vulnerability allows unauthorized privileges to authenticated non-administrator users who have tmsh access. Traffix SDC There is no impact; these F5 products are not affected by this vulnerability. Security Advisory Status F5 Product Development has assigned ID 818709 (BIG-IP), ID 826393 (BIG-IQ) to this vulnerability. To determine if your product and version have been evaluated for this vulnerability, refer to the Applies to (see versions) box. To determine if your release is known to be vulnerable, the components or features that are affected by the vulnerability, and for information about releases, point releases, or hotfixes that address the vulnerability, refer to the following table. For more information about security advisory versioning, refer to K51812227: Understanding Security Advisory versioning. +-------------------+------+----------+----------+----------+------+----------+ | | |Versions |Fixes | |CVSSv3|Vulnerable| |Product |Branch|known to |introduced|Severity |score^|component | | | |be |in | |1 |or feature| | | |vulnerable| | | | | +-------------------+------+----------+----------+----------+------+----------+ | |15.x |15.0.0 - |15.1.0 | | | | | | |15.0.1 |15.0.1.4 | | | | | +------+----------+----------+ | | | |BIG-IP (LTM, AAM, |14.x |14.0.0 - |14.1.2.3 | | | | |AFM, Analytics, | |14.1.2 | | | | | |APM, ASM, DNS, Edge+------+----------+----------+ | | | |Gateway, FPS, GTM, |13.x |13.1.0 - |13.1.3.4 |High |7.8 |tmsh | |Link Controller, | |13.1.3 | | | | | |PEM, +------+----------+----------+ | | | |WebAccelerator) |12.x |12.1.0 - |12.1.5.1 | | | | | | |12.1.5 | | | | | | +------+----------+----------+ | | | | |11.x |11.5.2 - |11.6.5.2 | | | | | | |11.6.5 | | | | | +-------------------+------+----------+----------+----------+------+----------+ | |8.x |None |8.0.0 | | | | | +------+----------+----------+ | | | | |7.x |7.0.0 - |None | | | | | | |7.1.0 | | | | | |BIG-IQ Centralized +------+----------+----------+High |7.8 |tmsh | |Management |6.x |6.0.0 - |None | | | | | | |6.1.0 | | | | | | +------+----------+----------+ | | | | |5.x |5.2.0 - |Will not | | | | | | |5.4.0 |fix | | | | +-------------------+------+----------+----------+----------+------+----------+ |Traffix SDC |5.x |None |Not |Not |None |None | | | | |applicable|vulnerable| | | +-------------------+------+----------+----------+----------+------+----------+ ^1The CVSSv3 score link takes you to a resource outside of AskF5, and it is possible that the document may be removed without our knowledge. Recommended Actions If you are running a version listed in the Versions known to be vulnerable column, you can eliminate this vulnerability by upgrading to a version listed in the Fixes introduced in column. If the table lists only an older version than what you are currently running, or does not list a non-vulnerable version, then no upgrade candidate currently exists. Mitigation To mitigate this vulnerability, disable tmsh access for users with non-administrator roles and grant administrative access only through the BIG-IP Configuration utility. To complete this mitigation, perform one of the following procedures: Mitigating the vulnerability using the BIG-IP Configuration utility 1. Log in to the BIG-IP Configuration utility as the admin user. 2. Go to System > Users > User List. 3. Select the Resource Administrator you want to modify. 4. For Terminal Access select Disabled. 5. Select Update. Mitigating the vulnerability using tmsh 1. Log in to tmsh as the root user. 2. List the administrative users on your system. 3. Use the following command syntax to disable tmsh for a user: modify /auth user <user> shell none Note: <user> is the name of the user for whom you want to disable tmsh access. For example: modify /auth user test-user shell none Supplemental Information o K51812227: Understanding Security Advisory versioning o K41942608: Overview of Security Advisory articles o K4602: Overview of the F5 security vulnerability response policy o K4918: Overview of the F5 critical issue hotfix policy o K9502: BIG-IP hotfix and point release matrix o K13123: Managing BIG-IP product hotfixes (11.x - 15.x) o K15106: Managing BIG-IQ product hotfixes o K15113: BIG-IQ hotfix and point release matrix o K167: Downloading software and firmware from F5 o K9970: Subscribing to email notifications regarding F5 products o K9957: Creating a custom RSS feed to view new and updated documents o K21232150: Considerations for upgrading BIG-IQ or F5 iWorkflow systems - --------------------------END INCLUDED TEXT-------------------- You have received this e-mail bulletin as a result of your organisation's registration with AusCERT. The mailing list you are subscribed to is maintained within your organisation, so if you do not wish to continue receiving these bulletins you should contact your local IT manager. If you do not know who that is, please send an email to auscert@auscert.org.au and we will forward your request to the appropriate person. NOTE: Third Party Rights This security bulletin is provided as a service to AusCERT's members. As AusCERT did not write the document quoted above, AusCERT has had no control over its content. The decision to follow or act on information or advice contained in this security bulletin is the responsibility of each user or organisation, and should be considered in accordance with your organisation's site policies and procedures. AusCERT takes no responsibility for consequences which may arise from following or acting on information or advice contained in this security bulletin. NOTE: This is only the original release of the security bulletin. It may not be updated when updates to the original are made. If downloading at a later date, it is recommended that the bulletin is retrieved directly from the author's website to ensure that the information is still current. Contact information for the authors of the original document is included in the Security Bulletin above. If you have any questions or need further information, please contact them directly. Previous advisories and external security bulletins can be retrieved from: https://www.auscert.org.au/bulletins/ =========================================================================== Australian Computer Emergency Response Team The University of Queensland Brisbane Qld 4072 Internet Email: auscert@auscert.org.au Facsimile: (07) 3365 7031 Telephone: (07) 3365 4417 (International: +61 7 3365 4417) AusCERT personnel answer during Queensland business hours which are GMT+10:00 (AEST). On call after hours for member emergencies only. =========================================================================== -----BEGIN PGP SIGNATURE----- Comment: http://www.auscert.org.au/render.html?it=1967 iQIVAwUBYV/aIuNLKJtyKPYoAQjhow//WuRvehj127/r/KjsY3kCV+pRC1SZkMl3 +oVBNtR5uUxkuGwOWMbvykVwN0q8GWKj/qwKxJQ7xIHQ0WRi8fyDZbjJiMmS8fGe 9QRaNxLDAeC8bXmdVAaBns204KQOJYV4DuoC2jt15yx0Pg2lAwP6pr+FRXWzHOV2 xy4WZmV+LEc5C8t5qOikruunB5STZbcmJftamFPLfIcjj7lP9sisdriJVqRlkCr5 qi0gVAqoSLMSO/huHiBFXye/w4dIL6Qo5B9RAV6Mjt3nHsbwJzBN6FiMq8PaSsSf dQynhetrvwOyzG09a1iuYG7ucuFUCz0OgyQuHNsgNh4mxirPHv2V7AAadWgRlmkl bwFgDL6i0chMvtdJgtfIwmUEba5eiQ2J2a34Yk0H/51e/yaDAzshcnvabQZiQcBt oEEEaMCd6leQ03/8ULNPyd4oWdIk8xXjYCcz7HoGdWhm722uJPHlC68Wszwq2E5g hmIZro0GDMo3qaIgmtrzymyaj/v3Q0neKoofZEKlb3tPfmBC5sKyKtvWm/7p101Y koLwflpycaPvAdx6L1tIkp1evCxYMRIZlOyAXNk9pMrtcLI4QHJ9gsE8SqTOO5Fo HXUpNOFrBLHhA4JyKCpZ39f8y8sYdVyt9UYHCHz/1hyOwYyr5+rjfuA7QTqgVYYb K47+wiOyGHw= =hjen -----END PGP SIGNATURE-----