Updated cups packages that fix a denial of service vulnerability are now available.
The Common UNIX Printing System (CUPS) is a print spooler. Alvaro Martinez Echevarria reported a bug in the CUPS Internet Printing Protocol (IPP) implementation in versions of CUPS prior to 1.1.21. An attacker could send a carefully crafted UDP packet to the IPP port which could cause CUPS to stop listening to the port and result in a denial of service. In order to exploit this bug, an attacker would need to have the ability to send a UDP packet to the IPP port (by default 631). The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CAN-2004-0558 to this issue. All users of cups should upgrade to these updated packages, which contain a backported patch as well as a fix for a non-exploitable off-by-one bug.