regenrecht has discovered a security issue affecting CUPS printing system, that was reported to CUPS upstream via iDefense: CUPS serves an interface on TCP port 631, which provides access to several CGI applications. These applications are used to administer CUPS, and to provide information about print jobs. These applications all use a common search function called cgiCompileSearch(). This function takes a user provided search expression, and compiles it into a regular expression. By passing a malformed search request, an attacker can trigger a heap based buffer overflow. In order to exploit this vulnerability remotely, the targeted host must be sharing a printer(s) on the network. If a printer is not being shared, CUPS only listens on the localhost interface, and the scope of this vulnerability would be limited to local privilege escalation. Versions affected: CUPS 1.2.0 through 1.3.6 Upstream bug report: http://www.cups.org/str.php?L2729 Acknowledgements: Red Hat would like to thank "regenrecht" for reporting this issue.
Created attachment 296901 [details] Upstream patch
This issue does not affect the version of cups as shipped in Red Hat Enterprise Linux 3 or 4 (no help.cgi). In Red Hat Enterprise Linux 5, help.cgi is included (as a PIE executable) and runs as user lp group lp.
For CVSS v2 score using Access Vector: Local because by default the tcp administrator interface is bound to localhost. cvss2=4.6/AV:L/AC:L/Au:N/C:P/I:P/A:P
Downgrading to moderate severity. By default on RHEL, CUPS binds the tcp administration interface to localhost. Successful exploitation of this flaw would yield user 'lp' group 'lp' privileges, but confined by the targeted SELinux policy, enabled by default.
Public now via APPLE-SA-2008-03-18: http://lists.apple.com/archives/security-announce/2008/Mar/msg00001.html Lifting embargo.
cups-1.2.12-10.fc7 has been submitted as an update for Fedora 7
cups-1.3.6-4.fc8 has been pushed to the Fedora 8 stable repository. If problems still persist, please make note of it in this bug report.
cups-1.2.12-10.fc7 has been pushed to the Fedora 7 stable repository. If problems still persist, please make note of it in this bug report.
This issue was addressed in: Red Hat Enterprise Linux: http://rhn.redhat.com/errata/RHSA-2008-0192.html Fedora: https://admin.fedoraproject.org/updates/F7/FEDORA-2008-2897 https://admin.fedoraproject.org/updates/F8/FEDORA-2008-2131