CVE 2009-0949
The ippReadIO function in cups/ipp.c in cupsd in CUPS before 1.3.10 does not properly initialize memory for IPP request packets, which allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via a scheduler request with two consecutive IPP_TAG_UNSUPPORTED tags.
See the 
CVE page on Mitre.org
for more details.
