CVE-2006-1242: Linux Kernel

Medium severity, CVSS 5.0. EPSS: 3.5% chance of exploitation in the next 30 days.

The ip_push_pending_frames function in Linux 2.4.x and 2.6.x before 2.6.16 increments the IP ID field when sending a RST after receiving unsolicited TCP SYN-ACK packets, which allows remote attackers to conduct an Idle Scan (nmap -sI) attack, which bypasses intended protections against such attacks.

Affected products

• Linux Linux Kernel: version 2.4.0 only; version 2.4.1 only; version 2.4.2 only; version 2.4.3 only; version 2.4.4 only; version 2.4.5 only; …

Published 2006-03-15. Last modified 2026-06-16.