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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2019.4305.3 TMM vulnerability CVE-2019-6660 10 January 2020 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: F5 BIG-IP products Publisher: F5 Networks Operating System: Network Appliance Impact/Access: Denial of Service -- Remote/Unauthenticated Resolution: Patch/Upgrade CVE Names: CVE-2019-6660 Original Bulletin: https://support.f5.com/csp/article/K23860356 Revision History: January 10 2020: Vendor provided additional mitigation instructions. November 22 2019: Clarified the Security Advisory Description section November 15 2019: Initial Release - --------------------------BEGIN INCLUDED TEXT-------------------- K23860356: TMM vulnerability CVE-2019-6660 Original Publication Date: 15 Nov, 2019 Latest Publication Date: 08 Jan, 2020 Security Advisory Description iRules performing HTTP header manipulation may cause a denial-of-service(DoS) when processing traffic handled by a virtual server with an associated HTTP profile, in specific circumstances, when the requests do not strictly conform to RFCs.(CVE-2019-6660) Impact The affected BIG-IP system's Traffic Management Microkernel (TMM) process enters a loop when handling malformed HTTP requests, and this may result in an interruption in traffic processing. If the BIG-IP system is part of a high availability (HA) group, a device failover may occur. Security Advisory Status F5 Product Development has assigned ID 767653 (BIG-IP) 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 |None |15.0.0 | | | | | +------+----------+----------+ | | | | | |14.1.0 - | | | | | | |14.x |14.1.2 |14.1.2.1 | | | | |BIG-IP (LTM, AAM, | |14.0.0 - |14.0.1.1 | | | | |AFM, Analytics, | |14.0.1 | | | | | |APM, ASM, DNS, Edge+------+----------+----------+ | | | |Gateway, FPS, GTM, |13.x |13.1.0 - |13.1.3 |High |7.5 |TMM | |Link Controller, | |13.1.1 | | | | | |PEM, +------+----------+----------+ | | | |WebAccelerator) |12.x |None |Not | | | | | | | |applicable| | | | | +------+----------+----------+ | | | | |11.x |None |Not | | | | | | | |applicable| | | | +-------------------+------+----------+----------+----------+------+----------+ |Enterprise Manager |3.x |None |Not |Not |None |None | | | | |applicable|vulnerable| | | +-------------------+------+----------+----------+----------+------+----------+ | |7.x |None |Not | | | | | | | |applicable| | | | | +------+----------+----------+ | | | |BIG-IQ Centralized |6.x |None |Not |Not |None |None | |Management | | |applicable|vulnerable| | | | +------+----------+----------+ | | | | |5.x |None |Not | | | | | | | |applicable| | | | +-------------------+------+----------+----------+----------+------+----------+ |F5 iWorkflow |2.x |None |Not |Not |None |None | | | | |applicable|vulnerable| | | +-------------------+------+----------+----------+----------+------+----------+ |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. Security Advisory 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, you can modify any iRule that performs HTTP header manipulation on the affected virtual server, to stop processing when the system detects an HTTP request that uses version HTTP/0.9. An example of an iRules statement that detects and stops the processing of an HTTP request that uses version HTTP/0.9 may appear as follows: if {[HTTP::version] equals "0.9"} {return} For the mitigation to be effective, you have to: 1. Use the iRules statement in existing iRules that preform HTTP header manipulation. 2. Insert the iRules statement at the top of HTTP iRule events. You can insert the statement into an existing iRule that handles HTTP requests for the affected virtual server. For example, take the following rule: ltm rule /Common/My_Existing_iRule { when HTTP_REQUEST { #<Existing iRule statements> } } Insert the statement if {[HTTP::version] equals "0.9"} {return} at the top of the HTTP event: ltm rule /Common/My_Existing_iRule { when HTTP_REQUEST { if {[HTTP::version] equals "0.9"} {return} #<Existing iRule statements> } } - --------------------------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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