CVE-2009-4016: Ircd-Hybrid

Medium severity, CVSS 6.8. EPSS: 4% chance of exploitation in the next 30 days.

Integer underflow in the clean_string function in irc_string.c in (1) IRCD-hybrid 7.2.2 and 7.2.3, (2) ircd-ratbox before 2.2.9, and (3) oftc-hybrid before 1.6.8, when flatten_links is disabled, allows remote attackers to execute arbitrary code or cause a denial of service (daemon crash) via a LINKS command.

Affected products

• Ircd-Hybrid Ircd-Hybrid: version 7.2.2 only; version 7.2.3 only
• Ircd-Ratbox Ircd-Ratbox: up to and including 2.2.8; version 1.0 only; version 1.1 only; version 1.1.1 only; version 1.1.2 only; version 1.2.1 only; …
• Oftc Oftc-Hybrid: up to and including 1.6.7; version 1.4.0 only; version 1.4.1 only; version 1.5.0 only; version 1.5.1 only; version 1.5.2 only; …

Published 2010-02-04. Last modified 2026-06-16.