(RHSA-2005:053) CUPS security update

The Common UNIX Printing System provides a portable printing layer for
UNIX® operating systems.

During a source code audit, Chris Evans and others discovered a number of
integer overflow bugs that affected all versions of Xpdf, which also
affects CUPS due to a shared codebase. An attacker could construct a
carefully crafted PDF file that could cause CUPS to crash or possibly
execute arbitrary code when opened. This issue was assigned the name
CAN-2004-0888 by The Common Vulnerabilities and Exposures project
(cve.mitre.org). Red Hat Enterprise Linux 4 contained a fix for this issue,
but it was found to be incomplete and left 64-bit architectures vulnerable.
The Common Vulnerabilities and Exposures project (cve.mitre.org) has
assigned the name CAN-2005-0206 to this issue.

A buffer overflow flaw was found in the Gfx::doImage function of Xpdf which
also affects the CUPS pdftops filter due to a shared codebase. An attacker
who has the ability to send a malicious PDF file to a printer could
possibly execute arbitrary code as the “lp” user. The Common
Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name
CAN-2004-1125 to this issue.

A buffer overflow flaw was found in the ParseCommand function in the
hpgltops program. An attacker who has the ability to send a malicious HPGL
file to a printer could possibly execute arbitrary code as the “lp” user.
The Common Vulnerabilities and Exposures project (cve.mitre.org) has
assigned the name CAN-2004-1267 to this issue.

A buffer overflow flaw was found in the Decrypt::makeFileKey2 function of
Xpdf which also affects the CUPS pdftops filter due to a shared codebase.
An attacker who has the ability to send a malicious PDF file to a printer
could possibly execute arbitrary code as the “lp” user. The Common
Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name
CAN-2005-0064 to this issue.

The lppasswd utility was found to ignore write errors when modifying the
CUPS passwd file. A local user who is able to fill the associated file
system could corrupt the CUPS password file or prevent future uses of
lppasswd. The Common Vulnerabilities and Exposures project (cve.mitre.org)
has assigned the names CAN-2004-1268 and CAN-2004-1269 to these issues.

The lppasswd utility was found to not verify that the passwd.new file is
different from STDERR, which could allow local users to control output to
passwd.new via certain user input that triggers an error message. The
Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned
the name CAN-2004-1270 to this issue.

All users of cups should upgrade to these updated packages, which contain
backported patches to resolve these issues.