Low: busybox (SL6)

Synopsis: Low: busybox security and bug fix update
Issue Date: 2012-06-20
CVE Numbers: CVE-2006-1168

BusyBox provides a single binary that includes versions of a large number
of system commands, including a shell. This can be very useful for
recovering from certain types of system failures, particularly those
involving broken shared libraries.

A buffer underflow flaw was found in the way the uncompress utility of
BusyBox expanded certain archive files compressed using Lempel-Ziv
compression. If a user were tricked into expanding a specially-crafted
archive file with uncompress, it could cause BusyBox to crash or,
potentially, execute arbitrary code with the privileges of the user
running BusyBox. (CVE-2006-1168)

The BusyBox DHCP client, udhcpc, did not sufficiently sanitize certain
options provided in DHCP server replies, such as the client hostname. A
malicious DHCP server could send such an option with a specially-crafted
value to a DHCP client. If this option’s value was saved on the client
system, and then later insecurely evaluated by a process that assumes the
option is trusted, it could lead to arbitrary code execution with the
privileges of that process. Note: udhcpc is not used on Red Hat Enterprise
Linux by default, and no DHCP client script is provided with the busybox
packages. (CVE-2011-2716)

This update also fixes the following bugs:

* Prior to this update, the “findfs” command did not recognize Btrfs
partitions. As a consequence, an error message could occur when dumping a
core file. This update adds support for recognizing such partitions so
the problem no longer occurs. (BZ#751927)

* If the “grep” command was used with the “-F” and “-i” options at the
same time, the “-i” option was ignored. As a consequence, the “grep -iF”
command incorrectly performed a case-sensitive search instead of an
insensitive search. A patch has been applied to ensure that the combination
of the “-F” and “-i” options works as expected. (BZ#752134)

* Prior to this update, the msh shell did not support the “set -o pipefail”
command. This update adds support for this command. (BZ#782018)

* Previously, the msh shell could terminate unexpectedly with a
segmentation fault when attempting to execute an empty command as a result
of variable substitution (for example msh -c ‘$nonexistent_variable’).
With this update, msh has been modified to correctly interpret such
commands and no longer crashes in this scenario. (BZ#809092)

* Previously, the msh shell incorrectly executed empty loops. As a
consequence, msh never exited such a loop even if the loop condition was
false, which could cause scripts using the loop to become unresponsive.
With this update, msh has been modified to execute and exit empty loops
correctly, so that hangs no longer occur. (BZ#752132)

All users of busybox are advised to upgrade to these updated packages,
which contain backported patches to fix these issues.


– Scientific Linux Development Team