RHSA-2013:0132 - Security Advisory

Topic

An updated autofs package that fixes one security issue, several bugs, and
adds one enhancement is now available for Red Hat Enterprise Linux 5.

The Red Hat Security Response Team has rated this update as having low
security impact. A Common Vulnerability Scoring System (CVSS) base score,
which gives a detailed severity rating, is available from the CVE link in
the References section.

Description

The autofs utility controls the operation of the automount daemon. The
automount daemon automatically mounts and unmounts file systems.

A bug fix included in RHBA-2012:0264 introduced a denial of service flaw in
autofs. When using autofs with LDAP, a local user could use this flaw to
crash autofs, preventing future mount requests from being processed until
the autofs service was restarted. Note: This flaw did not impact existing
mounts (except for preventing mount expiration). (CVE-2012-2697)

Red Hat would like to thank Ray Rocker for reporting this issue.

This update also fixes the following bugs:

• The autofs init script sometimes timed out waiting for the automount

daemon to exit and returned a shutdown failure if the daemon failed to exit
in time. To resolve this problem, the amount of time that the init script
waits for the daemon has been increased to allow for cases where servers
are slow to respond or there are many active mounts. (BZ#585058)

• Due to an omission when backporting a change, autofs attempted to

download the entire LDAP map at startup. This mistake has now been
corrected. (BZ#767428)

• A function to check the validity of a mount location was meant to check

only for a small subset of map location errors. A recent modification in
error reporting inverted a logic test in this validating function.
Consequently, the scope of the test was widened, which caused the automount
daemon to report false positive failures. With this update, the faulty
logic test has been corrected and false positive failures no longer occur.
(BZ#798448)

• When there were many attempts to access invalid or non-existent keys, the

automount daemon used excessive CPU resources. As a consequence, systems
sometimes became unresponsive. The code has been improved so that automount
checks for invalid keys earlier in the process which has eliminated a
significant amount of the processing overhead. (BZ#847101)

• The auto.master(5) man page did not document the "-t, --timeout" option

in the FORMAT options section. This update adds this information to the man
page. (BZ#859890)

This update also adds the following enhancement:

• Previously, it was not possible to configure separate timeout values for

individual direct map entries in the autofs master map. This update adds
this functionality. (BZ#690404)

All users of autofs are advised to upgrade to this updated package, which
contains backported patches to correct these issues and add this
enhancement.

Solution

Before applying this update, make sure all previously-released errata
relevant to your system have been applied.

This update is available via the Red Hat Network. Details on how to
use the Red Hat Network to apply this update are available at
https://access.redhat.com/knowledge/articles/11258

Affected Products

• Red Hat Enterprise Linux Server 5 x86_64
• Red Hat Enterprise Linux Server 5 ia64
• Red Hat Enterprise Linux Server 5 i386
• Red Hat Enterprise Linux Workstation 5 x86_64
• Red Hat Enterprise Linux Workstation 5 i386
• Red Hat Enterprise Linux Desktop 5 x86_64
• Red Hat Enterprise Linux Desktop 5 i386
• Red Hat Enterprise Linux for IBM z Systems 5 s390x
• Red Hat Enterprise Linux for Power, big endian 5 ppc
• Red Hat Enterprise Linux Server from RHUI 5 x86_64
• Red Hat Enterprise Linux Server from RHUI 5 i386

Fixes

• BZ - 585058 - autofs5 init script times out before automount exits and incorrectly shows that autofs5 stop failed
• BZ - 643142 - "/net -hosts -fstype=nfs4" does not work while "/home /etc/auto.nfs4" works.
• BZ - 690404 - RFE: timeout option cannot be configured individually with multiple direct map entries
• BZ - 831772 - CVE-2012-2697 autofs: denial of service when using an LDAP-based automount map

CVEs

• CVE-2012-2697

References

• https://access.redhat.com/security/updates/classification/#low
• https://rhn.redhat.com/errata/RHBA-2012-0264.html