SOL17309 - Linux kernel vulnerability CVE-2015-5366

Note: As of February 17, 2015, AskF5 Security Advisory articles include the Severity value. Security Advisory articles published before this date do not list a Severity value.

Recommended Action

If the previous table lists a version in the Versions known to be not vulnerable column, you can eliminate this vulnerability by upgrading to the listed version. If the listed version is older than the version you are currently running, or if the table does not list any version in the column, 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.

BIG-IP, BIG-IQ, and Enterprise Manager

To mitigate this vulnerability, you should only permit management access to F5 products over a secure network, and restrict command line access for affected systems to the trusted users. For more information, refer to the following articles:

• SOL13309: Restricting access to the Configuration utility by source IP address (11.x)
• SOL7448: Restricting access to the Configuration utility by source IP address (9.x - 10.x)
• SOL13092: Overview of securing access to the BIG-IP system

FirePass

To protect against undesired UDP traffic, you should use a front-end firewall.

Traffix SDC

To mitigate this vulnerability, you should perform the following actions:

• When possible, remove the iptables entries that allow traffic for the following UDP services:

  • **Syslog **
    -A INPUT -i eth0 -p udp -m udp --dport 514 -m comment --comment “SYSLOG” -j ACCEPT

  • **SIP **
    -A INPUT -p udp -m udp --dport 5060 -m comment --comment “SIP protocol” -j ACCEPT

  • **Diameter **
    -A INPUT -d 192.168.1.71/32 -i eth0 -p udp -m udp --dport 3868 -j ACCEPT

• Add source validation on iptables entries when allowing traffic on the following UDP service:

  • **SNMP **
    -A INPUT -i eth0 -p udp -m udp --dport 161 -m comment --comment “statistics by SNMP” -j ACCEPT
    -A INPUT -d 192.168.1.74/32 -i eth0 -p udp -m udp --dport 162 -m comment --comment “SNMP TRAPS” -j ACCEPT

• Apply anti-spoofing rules in the upstream firewalls.

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