Scientific Linux Security Update : bash on SL5.x i386/x86_64

This script is Copyright (C) 2012 Tenable Network Security, Inc.


Synopsis :

The remote Scientific Linux host is missing a security update.

Description :

Bash is the default shell for Scientific Linux.

It was found that certain scripts bundled with the Bash documentation
created temporary files in an insecure way. A malicious, local user
could use this flaw to conduct a symbolic link attack, allowing them
to overwrite the contents of arbitrary files accessible to the victim
running the scripts. (CVE-2008-5374)

This update fixes the following bugs :

- When using the source builtin at location '.',
occasionally, bash opted to preserve internal
consistency and abort scripts. This caused bash to abort
scripts that assigned values to read-only variables.
This is now fixed to ensure that such scripts are now
executed as written and not aborted.

- When the tab key was pressed for auto-completion options
for the typed text, the cursor moved to an unexpected
position on a previous line if the prompt contained
characters that cannot be viewed and a '\]'. This is now
fixed to retain the cursor at the expected position at
the end of the target line after autocomplete options
correctly display.

- Bash attempted to interpret the NOBITS .dynamic section
of the ELF header. This resulted in a '^D: bad ELF
interpreter: No such file or directory' message. This is
fixed to ensure that the invalid '^D' does not appear in
the error message.

- The $RANDOM variable in Bash carried over values from a
previous execution for later jobs. This is fixed and the
$RANDOM variable generates a new random number for each
use.

- When Bash ran a shell script with an embedded null
character, bash's source builtin parsed the script
incorrectly. This is fixed and bash's source builtin
correctly parses shell script null characters.

- The bash manual page for 'trap' did not mention that
signals ignored upon entry cannot be listed later. The
manual page was updated for this update and now
specifically notes that 'Signals ignored upon entry to
the shell cannot be trapped, reset or listed'.

- Bash's readline incorrectly displayed additional text
when resizing the terminal window when text spanned more
than one line, which caused incorrect display output.
This is now fixed to ensure that text in more than one
line in a resized window displays as expected.

- Previously, bash incorrectly displayed 'Broken pipe'
messages for builtins like 'echo' and 'printf' when
output did not succeed due to EPIPE. This is fixed to
ensure that the unnecessary 'Broken pipe' messages no
longer display.

- Inserts with the repeat function were not possible after
a deletion in vi-mode. This has been corrected and, with
this update, the repeat function works as expected after
a deletion.

- In some situations, bash incorrectly appended '/' to
files instead of just directories during tab-completion,
causing incorrect auto-completions. This is fixed and
auto-complete appends '/' only to directories.

- Bash had a memory leak in the 'read' builtin when the
number of fields being read was not equal to the number
of variables passed as arguments, causing a shell script
crash. This is fixed to prevent a memory leak and shell
script crash.

- /usr/share/doc/bash-3.2/loadables in the bash package
contained source files which would not build due to
missing C header files. With this update, the unusable
(and unbuildable) source files were removed from the
package.

This update also adds the following enhancement :

- The system-wide '/etc/bash.bash_logout' bash logout file
is now enabled. This allows administrators to write
system-wide logout actions for all users.

Users of bash are advised to upgrade to this updated package, which
contains backported patches to resolve these issues and add this
enhancement.

See also :

http://www.nessus.org/u?5047e362

Solution :

Update the affected bash package.

Risk factor :

Medium / CVSS Base Score : 6.9
(CVSS2#AV:L/AC:M/Au:N/C:C/I:C/A:C)

Family: Scientific Linux Local Security Checks

Nessus Plugin ID: 61088 ()

Bugtraq ID:

CVE ID: CVE-2008-5374