The MITRE CVE dictionary describes this issue as:
Buffer overflow in X.org libXvMC 1.0.7 and earlier allows X servers to cause a denial of service (crash) and possibly execute arbitrary code via crafted length or index values to the XvMCGetDRInfo function.
Find out more about CVE-2013-1999 from the
MITRE CVE dictionary dictionary and
This issue affects the libXvMC package in Red Hat Enterprise Linux 5. Red Hat Product Security has rated this issue as having Moderate security impact. This issue is not planned to be fixed in Red Hat Enterprise Linux 5 as it is now in Production 3 Phase of the support and maintenance life cycle: https://access.redhat.com/support/policy/updates/errata/