|Summary:||CVE-2010-2431 cups: latent privilege escalation vulnerability|
|Product:||[Other] Security Response||Reporter:||Vincent Danen <vdanen>|
|Component:||vulnerability||Assignee:||Red Hat Product Security <security-response-team>|
|Status:||CLOSED ERRATA||QA Contact:|
|Version:||unspecified||CC:||jlieskov, jpopelka, jrusnack, twaugh, ykopkova|
|Fixed In Version:||Doc Type:||Bug Fix|
|Doc Text:||Story Points:||---|
|Last Closed:||2010-10-29 07:36:56 UTC||Type:||---|
|oVirt Team:||---||RHEL 7.3 requirements from Atomic Host:|
|Cloudforms Team:||---||Target Upstream Version:|
|Bug Depends On:||604728, 605399, 646767, 646768|
Description Vincent Danen 2010-06-17 20:27:36 UTC
Quoting from the upstream bug report http://cups.org/str.php?L3510: directory that is writable by unprivileged processes. This is a latent privilege escalation vulnerability. It can be exploited only in the presence of other CUPS vulnerabilities. Why this is privilege escalation -------------------------------- This is privilege escalation, because an unprivileged process can trick the CUPS server into overwriting arbitrary files as root. Example: drwxrwxr-x 4 root lp /var/cache/cups -rw-r----- 1 root lp /var/cache/cups/remote.cache This file is opened with cupsFileOpen() which simply opens the file with open(filename, O_WRONLY | O_TRUNC | O_CREAT | O_LARGEFILE | O_BINARY, 0666). If a CUPS "external" program has a vulnerability, an attacker can use the group=lp privileges to replace /var/cache/cups/remote.cache with a symlink to a root-writable file. CUPS will then overwrite that file as root. A similar latent vulnerability exists for the state file /var/cache/cups/job.cache. Why this is a latent vulnerability ---------------------------------- This is a latent vulnerability, because there is no known exploit for CUPS "external" programs that run as user=lp, group=lp. The upstream fix looks more like a preventative fix as there does not seem to be anything exploitable here, so this looks like more a hardening than a response to an actual flaw.
Comment 2 Vincent Danen 2010-06-17 20:34:24 UTC
Created cups tracking bugs for this issue Affects: fedora-all [bug 605399]
Comment 3 Fedora Update System 2010-06-18 11:03:24 UTC
cups-1.4.4-1.fc13 has been submitted as an update for Fedora 13. http://admin.fedoraproject.org/updates/cups-1.4.4-1.fc13
Comment 4 Fedora Update System 2010-06-18 11:04:24 UTC
cups-1.4.4-1.fc12 has been submitted as an update for Fedora 12. http://admin.fedoraproject.org/updates/cups-1.4.4-1.fc12
Comment 5 Fedora Update System 2010-06-18 11:05:00 UTC
cups-1.4.4-1.fc11 has been submitted as an update for Fedora 11. http://admin.fedoraproject.org/updates/cups-1.4.4-1.fc11
Comment 6 Jan Lieskovsky 2010-06-23 10:33:32 UTC
Common Vulnerabilities and Exposures assigned an identifier CVE-2010-2431 to this vulnerability: The cupsFileOpen function in CUPS before 1.4.4 allows local users, with lp group membership, to overwrite arbitrary files via a symlink attack on the (1) /var/cache/cups/remote.cache or (2) /var/cache/cups/job.cache file. With references:  http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2010-2431  http://cups.org/articles.php?L596  http://cups.org/str.php?L3510
Comment 9 Fedora Update System 2010-06-24 12:22:33 UTC
cups-1.4.4-4.fc13 has been submitted as an update for Fedora 13. http://admin.fedoraproject.org/updates/cups-1.4.4-4.fc13
Comment 10 Fedora Update System 2010-06-25 18:10:23 UTC
cups-1.4.4-4.fc11 has been pushed to the Fedora 11 stable repository. If problems still persist, please make note of it in this bug report.
Comment 11 Fedora Update System 2010-07-01 18:44:22 UTC
cups-1.4.4-5.fc13 has been pushed to the Fedora 13 stable repository. If problems still persist, please make note of it in this bug report.
Comment 12 Fedora Update System 2010-07-27 02:45:54 UTC
cups-1.4.4-5.fc12 has been pushed to the Fedora 12 stable repository. If problems still persist, please make note of it in this bug report.
Comment 16 errata-xmlrpc 2010-10-29 01:44:15 UTC
This issue has been addressed in following products: Red Hat Enterprise Linux 5 Via RHSA-2010:0811 https://rhn.redhat.com/errata/RHSA-2010-0811.html
Comment 17 Vincent Danen 2010-10-29 02:58:02 UTC
Statement: This issue did not affect the versions of CUPS as shipped with Red Hat Enterprise Linux 3 or 4. It was addressed in Red Hat Enterprise Linux 5 via RHSA-2010:0811.