CVE-2013-6424: Canonical Ubuntu Linux

Medium severity, CVSS 5.0. EPSS: 2.9% chance of exploitation in the next 30 days.

Integer underflow in the xTrapezoidValid macro in render/picture.h in X.Org allows context-dependent attackers to cause a denial of service (crash) via a negative bottom value.

Affected products

• Canonical Ubuntu Linux: version 12.04 only; version 14.04 only; version 14.10 only
• Debian Debian Linux: version 6.0 only; version 7.0 only
• Opensuse Opensuse: version 12.2 only; version 12.3 only; version 13.1 only
• Pixman Pixman: before 0.31.2 (fixed in 0.31.2)

Published 2014-01-18. Last modified 2026-06-17.