CVE-2008-4109: OpenBSD OpenSSH

Medium severity, CVSS 5.0. EPSS: 28.4% chance of exploitation in the next 30 days.

A certain Debian patch for OpenSSH before 4.3p2-9etch3 on etch; before 4.6p1-1 on sid and lenny; and on other distributions such as SUSE uses functions that are not async-signal-safe in the signal handler for login timeouts, which allows remote attackers to cause a denial of service (connection slot exhaustion) via multiple login attempts. NOTE: this issue exists because of an incorrect fix for CVE-2006-5051.

Affected products

• OpenBSD OpenSSH: up to and including 4.3p2; version 1.2 only; version 1.2.1 only; version 1.2.2 only; version 1.2.3 only; version 1.2.27 only; …

Published 2008-09-18. Last modified 2026-06-16.