USN-50-1: CUPS vulnerabilities

23 December 2004

cupsys vulnerabilities

A security issue affects these releases of Ubuntu and its derivatives:

  • Ubuntu 4.10

Software Description



The recent USN-48-1 fixed a buffer overflow in xpdf. Since CUPS contains xpdf code to convert incoming PDF files to the PostScript format, this vulnerability applies to cups as well.

In this case it could even lead to privilege escalation: if an attacker submitted a malicious PDF file for printing, he could be able to execute arbitrary commands with the privileges of the CUPS server.

Please note that the Ubuntu version of CUPS runs as a minimally privileged user ‘cupsys’ by default, so there is no possibility of root privilege escalation. The privileges of the ‘cupsys’ user are confined to modifying printer configurations, altering print jobs, and controlling printers.


Ariel Berkman discovered a buffer overflow in the ParseCommand() function of the HPGL input driver. If an attacker printed a malicious HPGL file, they could exploit this to execute arbitrary commands with the privileges of the CUPS server.

CAN-2004-1268, CAN-2004-1269, CAN-2004-1270:

Bartlomiej Sieka discovered three flaws in lppasswd. These allowed users to corrupt the new password file by filling up the disk, sending certain signals, or closing the standard output and/or error streams.

Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 4.10

To update your system, please follow these instructions: