libx11 - security update

Abhishek Arya discovered a buffer overflow in the MakeBigReq macro
provided by libx11, which could result in denial of service or the
execution of arbitrary code.

Several other xorg packages (e.g. libxrender) will be recompiled against
the fixed package after the release of this update. For detailed
information on the status of recompiled packages please refer to the
Debian Security Tracker at
CVE-2013-7439

For the oldstable distribution (squeeze), this problem has been fixed
in version 2:1.3.3-4+squeeze2.

For the stable distribution (wheezy), this problem has been fixed in
version 2:1.5.0-1+deb7u2.