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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2016.0060 SOL22843911: F5 Path MTU Discovery vulnerability CVE-2015-7759 11 January 2016 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: F5 BIG-IP APM Publisher: F5 Operating System: Network Appliance Impact/Access: Denial of Service -- Remote/Unauthenticated Resolution: Patch/Upgrade CVE Names: CVE-2015-7759 Original Bulletin: https://support.f5.com/kb/en-us/solutions/public/k/22/sol22843911.html - --------------------------BEGIN INCLUDED TEXT-------------------- SOL22843911: F5 Path MTU Discovery vulnerability CVE-2015-7759 Security AdvisorySecurity Advisory Original Publication Date: 01/07/2016 Vulnerability Description A remote attacker may be able to cause the Traffic Management Microkernel (TMM) to restart using maliciously constructed ICMP packets. (CVE-2015-7759 - reserved) Virtual servers using a TCP profile configured with Congestion Metrics Cache enabled are affected by this vulnerability. Congestion Metrics Cache is enabled by default for TCP profiles. Impact The BIG-IP system may temporarily fail to process traffic as it recovers from the Traffic Management Microkernel (TMM) restart, and devices configured as a high-availability pair may fail over. Security Issue Status F5 Product Development has assigned ID 546140 (BIG-IP) to this vulnerability, and has evaluated the currently supported releases for potential vulnerability. 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 or hotfixes that address the vulnerability, refer to the following table: Product Versions known to be vulnerable Versions known to be not vulnerable Severity Vulnerable component or feature BIG-IP LTM 12.0.0 12.0.0 HF1 11.0.0 - 11.6.0 10.1.0 - 10.2.4 Severe TMM processing of virtual servers that use a TCP profile that has Congestion Metrics Cache enabled. BIG-IP AAM 12.0.0 12.0.0 HF1 11.4.0 - 11.6.0 Severe TMM processing of virtual servers that use a TCP profile that has Congestion Metrics Cache enabled. BIG-IP AFM 12.0.0 12.0.0 HF1 11.3.0 - 11.6.0 Severe TMM processing of virtual servers that use a TCP profile that has Congestion Metrics Cache enabled. BIG-IP Analytics 12.0.0 12.0.0 HF1 11.0.0 - 11.6.0 Severe TMM processing of virtual servers that use a TCP profile that has Congestion Metrics Cache enabled. BIG-IP APM 12.0.0 12.0.0 HF1 11.0.0 - 11.6.0 10.1.0 - 10.2.4 Severe TMM processing of virtual servers that use a TCP profile that has Congestion Metrics Cache enabled. BIG-IP ASM 12.0.0 12.0.0 HF1 11.0.0 - 11.6.0 10.1.0 - 10.2.4 Severe TMM processing of virtual servers that use a TCP profile that has Congestion Metrics Cache enabled. BIG-IP DNS None 12.0.0 Not vulnerable None BIG-IP Edge Gateway None 11.0.0 - 11.3.0 10.1.0 - 10.2.4 Not vulnerable None BIG-IP GTM None 11.0.0 - 11.6.0 10.1.0 - 10.2.4 Not vulnerable None BIG-IP Link Controller 12.0.0 12.0.0 HF1 11.0.0 - 11.6.0 10.1.0 - 10.2.4 Severe TMM processing of virtual servers that use a TCP profile that has Congestion Metrics Cache enabled. BIG-IP PEM 12.0.0 12.0.0 HF1 11.3.0 - 11.6.0 Severe TMM processing of virtual servers that use a TCP profile that has Congestion Metrics Cache enabled. BIG-IP PSM None 11.0.0 - 11.4.1 10.1.0 - 10.2.4 Not vulnerable None BIG-IP WebAccelerator None 11.0.0 - 11.3.0 10.1.0 - 10.2.4 Not vulnerable None BIG-IP WOM None 11.0.0 - 11.3.0 10.1.0 - 10.2.4 Not vulnerable None ARX None 6.0.0 - 6.4.0 Not vulnerable None Enterprise Manager None 3.0.0 - 3.1.1 Not vulnerable None FirePass None 7.0.0 6.0.0 - 6.1.0 Not vulnerable None BIG-IQ Cloud None 4.0.0 - 4.5.0 Not vulnerable None BIG-IQ Device None 4.2.0 - 4.5.0 Not vulnerable None BIG-IQ Security None 4.0.0 - 4.5.0 Not vulnerable None BIG-IQ ADC None 4.5.0 Not vulnerable None BIG-IQ Centralized Management None 4.6.0 Not vulnerable None BIG-IQ Cloud and Orchestration None 1.0.0 Not vulnerable None LineRate None 2.5.0 - 2.6.1 Not vulnerable None F5 WebSafe None 1.0.0 Not vulnerable None Traffix SDC None 4.0.0 - 4.4.0 3.3.2 - 3.5.1 Not vulnerable None Vulnerability 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 Versions known to be not vulnerable 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. F5 responds to vulnerabilities in accordance with the Severity values published in the previous table. The Severity values and other security vulnerability parameters are defined in SOL4602: Overview of the F5 security vulnerability response policy. To mitigate this vulnerability, you can disable the Congestion Metrics Cache setting (cmetrics-cache) for all TCP profiles on the BIG-IP system. To do so, use one of the following options: Using the Configuration utility, navigate to the Local Traffic > Profiles > Protocol > TCP page and select the profile you want to edit, and clear the Congestion Metrics Cache check box. - From the command line, use the following command syntax: tmsh modify ltm profile tcp <profile_name> cmetrics-cache disabled In the previous syntax, <profile_name> is the name of the tcp profile for which you are disabling Congestion Metrics Cache. Impact of action: The impact of the suggested mitigation depends on the specific environment. Disabling Congestion Metrics Cache in the TCP profiles may result in performance degradation, depending on network conditions. F5 recommends that you test any such changes during a maintenance window with consideration to the possible impact on your specific environment. Alternatively, if Path MTU Discovery (PMTU) functionality is not required, you could consider the following alternative actions: Block the ICMP Type 3 Code 4 (Fragmentation Needed) packets before they reach the BIG-IP system, by using an upstream firewall or BIG-IP AFM system. Block all ICMP traffic using an upstream firewall or the BIG-IP AFM system. Important: Blocking ICMP traffic prevents PMTU from functioning, and may impact other network services that rely on ICMP. F5 recommends that you evaluate the potential impact of blocking ICMP traffic in your environment. For information about blocking ICMP traffic with the BIG-IP AFM module, refer to the Deploying the BIG-IP Network Firewall in ADC Mode chapter of the BIG-IP Network Firewall: Policies and Implementations guide, and browse the Adding a firewall rule to deny ICMP section. Note: You cannot use BIG-IP packet filters to mitigate this vulnerability. Supplemental Information SOL9970: Subscribing to email notifications regarding F5 products SOL9957: Creating a custom RSS feed to view new and updated documents SOL4918: Overview of the F5 critical issue hotfix policy SOL167: Downloading software and firmware from F5 SOL13123: Managing BIG-IP product hotfixes (11.x - 12.x) SOL9502: BIG-IP hotfix matrix SOL12343: The SYN retransmission interval may vary when the Congestion Metrics Cache setting is enabled in the TCP profile - --------------------------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. 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If you have any questions or need further information, please contact them directly. Previous advisories and external security bulletins can be retrieved from: http://www.auscert.org.au/render.html?cid=1980 =========================================================================== 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 iQIVAwUBVpMuhH6ZAP0PgtI9AQIN1xAAhlbAeMrv7nfqjNje04/o1jzeY4x6Zp32 3VKEIleJmkH7+rKI1/sEmbLNGbetuMeBkuIqnNDwv07ZuuLs3twpqxxK7HXzeJ32 HqcBm/2mBu8NB7OLmjJNebMi/WgY9/LJYAlfMCsyF+CUa1A5VYuPR7NQOu3xcvYl mgpMosN0KPR+XYHbLonQjbu0IYXJoRMa0tf5qJ30WqPdDbq1H6RskE2nwAM/jVcp b/j0DXOno21H224vQjvs3+IFj5fXth0HCI3Lmx12hm91L/ZHqFw+7qy/bLtJcdUL KcgzNiIWBSj8QakGSnM05jHHjbNHzRyLaYch527dn/XFRDz0FBwbp14YLsHHf8uh rs+6hdmOLmEYyfBm7EylKuHz9WSSEU602+ZwJ3+L74SiL9qjD6SYGsnvxC6jq5FC eVKPDsSq1uyfZi9a8EklMeKZEF3oHEJSs2gOM1jrQPgfEkrsryFWXzG69X/Xdh7/ wU8M+72vOhERtbdivtaswm5pTb0cmwcGhfMLEx8oBF4si58EoXGgiCOqE/SfMZIW uS0idtsbbWWD3sAJGzog9Jf5LkeeXrH1KF0POOgf8ZUTi5tjMjOoiIKEsA282AE0 mB/EdmNeE0G1GVpZPThkPG6UC7+Jy5/3cb7CfOZpL8srHaSMQhSkIETO0JncTqsE 9JlEOI1ErsQ= =EvQG -----END PGP SIGNATURE-----