autofs (SL7)

Synopsis: Moderate: autofs security, bug fix and enhancement update
Advisory ID: SLSA-2015:2417-1
Issue Date: 2015-11-19
CVE Numbers: CVE-2014-8169

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.

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.

* 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.

* 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.

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.


– Scientific Linux Development Team