Bug 726691 (CVE-2011-2724)

Summary: CVE-2011-2724 samba, cifs-utils: mount.cifs incorrect fix for CVE-2010-0547
Product: [Other] Security Response Reporter: Jan Lieskovsky <jlieskov>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED ERRATA QA Contact:
Severity: low Docs Contact:
Priority: low    
Version: unspecifiedCC: azelinka, gdeschner, jlayton, prc, security-response-team
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard: public=20110729,reported=20110728,source=redhat,impact=low,cvss2=2.6/AV:L/AC:H/Au:N/C:N/I:P/A:P,rhel-4/samba=affected,rhel-5/samba=affected,rhel-5/samba3x=affected,rhel-6/samba=notaffected,rhel-6/cifs-utils=affected,fedora-all/cifs-utils=affected
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2011-08-30 03:25:55 EDT Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---
Bug Depends On: 722551, 722552, 722553, 722555, 722556, 725508, 725509, 726717    
Bug Blocks:    

Description Jan Lieskovsky 2011-07-29 09:51:11 EDT
Originally the CVE-2010-0547 identifier has been assigned by Common Vulnerabilities and Exposures to the following security issue:

client/mount.cifs.c in mount.cifs in smbfs in Samba 3.4.5 and earlier does not verify that the (1) device name and (2) mountpoint strings are composed of valid characters, which allows local users to cause a denial of service (mtab corruption) via a crafted string.

Later a bug was found in the upstream patch for this issue. More specifically:

check_mtab() calls check_newline() to check device and directory name.  check_newline() returns EX_USAGE (1) when error is detected, while check_mtab() expects -1 to indicate an error.

This bug in original CVE-2010-0547 fix (not to propagate the error properly) caused mount.cifs command on specially-crafted mount point (containing newline character) still to succeed and potentially, to corrupt mtab table on the systems, where CVE-2010-0296 glibc fix was not applied yet.

Proposed upstream patch by Jeff Layton:
[1] http://thread.gmane.org/gmane.linux.kernel.cifs/3827
Comment 1 Jan Lieskovsky 2011-07-29 09:53:57 EDT
This issue affects the versions of the samba package, as shipped with Red Hat Enterprise Linux 4 and 5.

--

This issue affects the version of the samba3x-package, as shipped with Red Hat Enterprise Linux 5.

--

This issue affects affects the version of the cifs-utils package, as shipped with Red Hat Enterprise Linux 6.

--

This issue affects the versions of the cifs-utils package, as shipped with Fedora release of 14 and 15.
Comment 2 Jan Lieskovsky 2011-07-29 10:59:03 EDT
The CVE identifier of CVE-2011-2724 has been assigned to this issue.
Comment 3 Jan Lieskovsky 2011-07-29 11:19:32 EDT
Created cifs-utils tracking bugs for this issue

Affects: fedora-all [bug 726717]
Comment 5 Tomas Hoger 2011-08-02 05:12:41 EDT
(In reply to comment #0)
> Originally the CVE-2010-0547 identifier has been assigned by Common
> Vulnerabilities and Exposures to the following security issue:

CVE-2010-0547 was previously tracked via bug #562156.

> This bug in original CVE-2010-0547 fix (not to propagate the error properly)
> caused mount.cifs command on specially-crafted mount point (containing newline
> character) still to succeed and potentially, to corrupt mtab table on the
> systems, where CVE-2010-0296 glibc fix was not applied yet.

The glibc fix for CVE-2010-0296 is already available for Red Hat Enterprise Linux 5 and 6, see also bug #562156, comment #5.

> Proposed upstream patch by Jeff Layton:
> [1] http://thread.gmane.org/gmane.linux.kernel.cifs/3827

Committed upstream as:
http://git.samba.org/?p=cifs-utils.git;a=commitdiff;h=1e7a32924b22d1f786b6f490ce8590656f578f91

(In reply to comment #1)
> This issue affects the versions of the samba package, as shipped with Red Hat
> Enterprise Linux 4 and 5.

Those packages are rather affected by the original CVE-2010-0547, as the incomplete fix was never released for those packages.
Comment 6 errata-xmlrpc 2011-08-29 13:27:31 EDT
This issue has been addressed in following products:

  Red Hat Enterprise Linux 5

Via RHSA-2011:1220 https://rhn.redhat.com/errata/RHSA-2011-1220.html
Comment 7 errata-xmlrpc 2011-08-29 13:38:30 EDT
This issue has been addressed in following products:

  Red Hat Enterprise Linux 6

Via RHSA-2011:1221 https://rhn.redhat.com/errata/RHSA-2011-1221.html