Bug 742907 (CVE-2011-3585) - CVE-2011-3585 Samba mtab lock file race condition
Summary: CVE-2011-3585 Samba mtab lock file race condition
Alias: CVE-2011-3585
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
Depends On:
Blocks: 742932
TreeView+ depends on / blocked
Reported: 2011-10-03 11:04 UTC by Jan Lieskovsky
Modified: 2019-09-29 12:48 UTC (History)
7 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Last Closed: 2011-10-17 15:48:10 UTC

Attachments (Terms of Use)

Description Jan Lieskovsky 2011-10-03 11:04:34 UTC
A race condition was found in the way 'mount.cifs' and 'umount.cifs' utilities performed mount / umount of a particular CIFS share to / from specified mount point (/etc/mtab~ lockfile was created before updating the /etc/mtab file and deleted once the operation completed), when these utilies were setuid root enabled. A local attacker could use this flaw to conduct denial of service attacks (failure of subsequent CIFS share umount / mount requests) by sending termination signal to 'mount.cifs' / 'umount.cifs' processes in the moment of existence of a stale (/etc/mtab~) lockfile.

[1] https://bugzilla.samba.org/show_bug.cgi?id=7179
    (upstream bug report)
[2] http://git.samba.org/?p=cifs-utils.git;a=commitdiff;h=810f7e4e0f2dbcbee0294d9b371071cb08268200
    (upstream patch)
[3] http://www.openwall.com/lists/oss-security/2011/09/27/1
    (CVE request)
[4] http://www.openwall.com/lists/oss-security/2011/09/30/5
    (CVE assignment)

Note: This flaw to be exploitable as described above requires the 'mount.cifs'
      / 'umount.cifs' utilities to be setuid root enabled. These utilities
      are not setuid root enabled on Red Hat Enterprise Linux and Fedora
      distributions, and thus these distributions as such are not vulnerable
      to this flaw.

Comment 6 Ramon de C Valle 2011-10-17 15:48:10 UTC
This issue has been addressed in following products:

  Red Hat Enterprise Linux 4
  Red Hat Enterprise Linux 5

Via RHSA-2011:1219 https://rhn.redhat.com/errata/RHSA-2011-1219.html

Comment 7 Ramon de C Valle 2011-10-20 15:42:45 UTC
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

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