CVE-2011-3188: F5 Arx

Critical severity, CVSS 9.1. EPSS: 5% chance of exploitation in the next 30 days.

The (1) IPv4 and (2) IPv6 implementations in the Linux kernel before 3.1 use a modified MD4 algorithm to generate sequence numbers and Fragment Identification values, which makes it easier for remote attackers to cause a denial of service (disrupted networking) or hijack network sessions by predicting these values and sending crafted packets.

Affected products

• F5 Arx: from 6.0.0, up to and including 6.4.0
• F5 BIG-IP Access Policy Manager: from 10.1.0, up to and including 10.2.4; from 11.0.0, up to and including 11.1.0
• F5 BIG-IP Analytics: from 11.0.0, up to and including 11.1.0
• F5 BIG-IP Application Security Manager: from 10.0.0, up to and including 10.2.4; from 11.0.0, up to and including 11.1.0
• F5 BIG-IP Edge Gateway: from 10.1.0, up to and including 10.2.4; from 11.0.0, up to and including 11.1.0
• F5 BIG-IP Global Traffic Manager: from 10.0.0, up to and including 10.2.4; from 11.0.0, up to and including 11.1.0
• F5 BIG-IP Link Controller: from 10.0.0, up to and including 10.2.4; from 11.0.0, up to and including 11.1.0
• F5 BIG-IP Local Traffic Manager: from 10.0.0, up to and including 10.2.4; from 11.0.0, up to and including 11.1.0
• F5 BIG-IP Protocol Security Module: from 10.0.0, up to and including 10.2.4; from 11.0.0, up to and including 11.1.0
• F5 BIG-IP WAN Optimization Manager: from 10.0.0, up to and including 10.2.4; from 11.0.0, up to and including 11.1.0
• F5 BIG-IP Webaccelerator: from 10.0.0, up to and including 10.2.4; from 11.0.0, up to and including 11.1.0
• F5 Enterprise Manager: from 2.1.0, up to and including 2.3.0; version 3.0.0 only
• F5 Firepass: from 6.0.0, up to and including 6.1.0; version 7.0.0 only
• Linux Linux Kernel: before 3.1 (fixed in 3.1)
• Red Hat Enterprise Linux: version 4.0 only

Published 2012-05-24. Last modified 2026-06-16.