An integer overflow issue has been reported in pixman prior to version 0.32.8. An attacker could cause an application using pixman to crash or, potentially, execute arbitrary code.
For Debian 7 Wheezy, these problems have been fixed in version 0.26.0-4+deb7u3.
We recommend that you upgrade your pixman packages.
Further information about Extended LTS security advisories can be found at: https://deb.freexian.com/extended-lts/