Integer underflow in the pixman_trapezoid_valid macro in pixman.h in Pixman before 0.32.0, as used in X.Org server and cairo, allows context-dependent attackers to cause a denial of service (crash) via a negative bottom value.

References

• https://nvd.nist.gov/vuln/detail/CVE-2013-6425
• https://bugs.freedesktop.org/show_bug.cgi?id=67484
• https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/1197921
• http://cgit.freedesktop.org/pixman/commit/?id=5e14da97f16e421d084a9e735be21b1025150f0c
• http://lists.freedesktop.org/archives/pixman/2013-November/003109.html
• http://lists.opensuse.org/opensuse-updates/2014-01/msg00001.html
• http://lists.opensuse.org/opensuse-updates/2014-01/msg00005.html
• http://lists.opensuse.org/opensuse-updates/2014-01/msg00008.html
• http://lists.opensuse.org/opensuse-updates/2014-01/msg00097.html
• http://rhn.redhat.com/errata/RHSA-2013-1869.html
• http://www.debian.org/security/2013/dsa-2823
• http://www.openwall.com/lists/oss-security/2013/12/03/8
• http://www.openwall.com/lists/oss-security/2013/12/04/8
• http://www.ubuntu.com/usn/USN-2047-1
• https://access.redhat.com/errata/RHSA-2013:1869
• https://access.redhat.com/security/cve/CVE-2013-6425
• https://bugzilla.redhat.com/show_bug.cgi?id=1037975