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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2021.1885.2 Python tarfile library vulnerability CVE-2019-20907 14 September 2021 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: BIG-IP (all modules) BIG-IQ Centralized Management F5OS Publisher: F5 Networks Operating System: Network Appliance Impact/Access: Denial of Service -- Existing Account Resolution: Mitigation CVE Names: CVE-2019-20907 Reference: ESB-2021.0927 ESB-2021.0899 Original Bulletin: https://support.f5.com/csp/article/K78284681 Revision History: September 14 2021: Vendor updated versions known to be vulnerable June 2 2021: Initial Release - --------------------------BEGIN INCLUDED TEXT-------------------- K78284681: Python tarfile library vulnerability CVE-2019-20907 Original Publication Date: 02 Jun, 2021 Latest Publication Date: 13 Sep, 2021 Security Advisory Description In Lib/tarfile.py in Python through 3.8.3, an attacker is able to craft a TAR archive leading to an infinite loop when opened by tarfile.open, because _proc_pax lacks header validation. (CVE-2019-20907) Impact A user-created custom Python script utilizing the Python tarfile library may enter an infinite loop, consuming resources and causing a denial of service. The Python tarfile library is not used by any standard F5-supplied software. Security Advisory Status F5 Product Development has assigned ID 1021245 (BIG-IP), ID 1020793 (BIG-IQ), and ID 1019165 (F5OS) 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. Note: After a fix is introduced for a given minor branch, that fix applies to all subsequent maintenance and point releases for that branch, and no additional fixes for that branch will be listed in the table. For example, when a fix is introduced in 14.1.2.3, the fix also applies to 14.1.2.4, and all later 14.1.x releases (14.1.3.x., 14.1.4.x). For more information, refer to K51812227: Understanding security advisory versioning. Additionally, software versions preceding those listed in the following table have reached the End of Technical Support (EoTS) phase of their lifecycle and are no longer evaluated for security issues. For more information, refer to the Security hotfixes section of K4602: Overview of the F5 security vulnerability response policy. +------------+------+--------------+----------+----------+------+-------------+ | | |Versions known|Fixes | |CVSSv3|Vulnerable | |Product |Branch|to be |introduced|Severity |score^|component or | | | |vulnerable^1 |in | |2 |feature | +------------+------+--------------+----------+----------+------+-------------+ | |16.x |16.0.0 - |None | | | | | | |16.0.1 | | | | | | +------+--------------+----------+ | | | | |15.x |15.1.0 - |None | | | | | | |15.1.3 | | | | | | +------+--------------+----------+ | | | | |14.x |14.1.0 - |None | | | | |BIG-IP (all | |14.1.4 | | | |Python | |modules) +------+--------------+----------+Medium^3 |4.4 |tarfile | | |13.x |13.1.0 - |None | | |library | | | |13.1.4 | | | | | | +------+--------------+----------+ | | | | |12.x |12.1.0 - |None | | | | | | |12.1.6 | | | | | | +------+--------------+----------+ | | | | |11.x |None |Not | | | | | | | |applicable| | | | +------------+------+--------------+----------+----------+------+-------------+ | |8.x |8.0.0 |None | | | | |BIG-IQ +------+--------------+----------+ | | | |Centralized |7.x |7.0.0 - 7.1.0 |None |Medium^3 |4.4 |None | |Management +------+--------------+----------+ | | | | |6.x |6.0.1 - 6.1.0 |None | | | | +------------+------+--------------+----------+----------+------+-------------+ |F5OS |1.x |1.1.0 - 1.1.4 |None |Medium^3 |4.4 |None | +------------+------+--------------+----------+----------+------+-------------+ |Traffix SDC |5.x |None |Not |Not |None |None | | | | |applicable|vulnerable| | | +------------+------+--------------+----------+----------+------+-------------+ ^1F5 evaluates only software versions that have not yet reached the End of Technical Support (EoTS) phase of their lifecycle. ^2The CVSSv3 score link takes you to a resource outside of AskF5, and it is possible that the document may be removed without our knowledge. ^3The specified products contain the affected code. However, F5 identifies the vulnerability status as Not vulnerable because the attacker cannot exploit the code in default, standard, or recommended configurations. Recommended Actions If you are running a version listed in the Versions known to be vulnerable column, you can eliminate this vulnerability by installing a version listed in the Fixes introduced in column. If the Fixes introduced in column does not list a version for your branch, then no update candidate currently exists for that branch and F5 recommends upgrading to a version with the fix (refer to the table). If the Fixes introduced in column lists a version prior to the one you are running, in the same branch, then your version should have the fix. Mitigation Avoid using custom-written scripts that utilize the Python tarfile libraries on F5 systems. Supplemental Information 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 K8986: F5 software lifecycle policy o K9502: BIG-IP hotfix and point release matrix o K13123: Managing BIG-IP product hotfixes (11.x - 16.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 - --------------------------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). 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