(RHSA-2015:2417) Moderate: autofs security, bug fix and enhancement update

The autofs utility controls the operation of the automount daemon. The
daemon automatically mounts file systems when in use and unmounts them when
they are not busy.

It was found that program-based automounter maps that used interpreted
languages such as Python used standard environment variables to locate
and load modules of those languages. A local attacker could potentially use
this flaw to escalate their privileges on the system. (CVE-2014-8169)

Note: This issue has been fixed by adding the “AUTOFS_” prefix to the
affected environment variables so that they are not used to subvert the
system. A configuration option (“force_standard_program_map_env”) to
override this prefix and to use the environment variables without the
prefix has been added. In addition, warnings have been added to the manual
page and to the installed configuration file. Now, by default the standard
variables of the program map are provided only with the prefix added to
its name.

Red Hat would like to thank the Georgia Institute of Technology for
reporting this issue.

Notably, this update fixes the following bugs:

• When the "ls " command was run in the root of an indirect mount, autofs
  attempted to literally mount the wildcard character () causing it to be
  added to the negative cache. If done before a valid mount, autofs then
  failed on further mount attempts inside the mount point, valid or not. This
  has been fixed, and wildcard map entries now function in the described
  situation. (BZ#1166457)

• When autofs encountered a syntax error consisting of a duplicate entry in
  a multimap entry, it reported an error and did not mount the map entry.
  With this update, autofs has been amended to report the problem in the log
  to alert the system administrator and use the last seen instance of the
  duplicate entry rather than fail. (BZ#1205600)

• In the ldap and sss lookup modules, the map reading functions did not
  distinguish between the “no entry found” and “service not available”
  errors. Consequently, when the “service not available” response was
  returned from a master map read, autofs did not update the mounts.
  An “entry not found” return does not prevent the map update, so the ldap
  and sss lookup modules were updated to distinguish between these two
  returns and now work as expected. (BZ#1233065)

In addition, this update adds the following enhancement:

• The description of the configuration parameter map_hash_table_size was
  missing from the autofs.conf(5) man page and its description in the
  configuration file comments was insufficient. A description of the
  parameter has been added to autofs.conf(5), and the configuration file
  comments have been updated. (BZ#1238573)

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