RHSA-2011:0027 - Security Advisory

Topic

Updated python packages that fix multiple security issues, several bugs,
and add two enhancements are now available for Red Hat Enterprise Linux 5.

The Red Hat Security Response Team has rated this update as having low
security impact. Common Vulnerability Scoring System (CVSS) base scores,
which give detailed severity ratings, are available for each vulnerability
from the CVE links in the References section.

Description

Python is an interpreted, interactive, object-oriented programming
language.

It was found that many applications embedding the Python interpreter did
not specify a valid full path to the script or application when calling the
PySys_SetArgv API function, which could result in the addition of the
current working directory to the module search path (sys.path). A local
attacker able to trick a victim into running such an application in an
attacker-controlled directory could use this flaw to execute code with the
victim's privileges. This update adds the PySys_SetArgvEx API. Developers
can modify their applications to use this new API, which sets sys.argv
without modifying sys.path. (CVE-2008-5983)

Multiple flaws were found in the Python rgbimg module. If an application
written in Python was using the rgbimg module and loaded a
specially-crafted SGI image file, it could cause the application to crash
or, possibly, execute arbitrary code with the privileges of the user
running the application. (CVE-2009-4134, CVE-2010-1449, CVE-2010-1450)

Multiple flaws were found in the Python audioop module. Supplying certain
inputs could cause the audioop module to crash or, possibly, execute
arbitrary code. (CVE-2010-1634, CVE-2010-2089)

This update also fixes the following bugs:

• When starting a child process from the subprocess module in Python 2.4,

the parent process could leak file descriptors if an error occurred. This
update resolves the issue. (BZ#609017)

• Prior to Python 2.7, programs that used "ulimit -n" to enable

communication with large numbers of subprocesses could still monitor only
1024 file descriptors at a time, which caused an exception:

ValueError: filedescriptor out of range in select()

This was due to the subprocess module using the "select" system call. The
module now uses the "poll" system call, removing this limitation.
(BZ#609020)

• Prior to Python 2.5, the tarfile module failed to unpack tar files if the

path was longer than 100 characters. This update backports the tarfile
module from Python 2.5 and the issue no longer occurs. (BZ#263401)

• The email module incorrectly implemented the logic for obtaining

attachment file names: the get_filename() fallback for using the deprecated
"name" parameter of the "Content-Type" header erroneously used the
"Content-Disposition" header. This update backports a fix from Python 2.6,
which resolves this issue. (BZ#644147)

• Prior to version 2.5, Python's optimized memory allocator never released

memory back to the system. The memory usage of a long-running Python
process would resemble a "high-water mark". This update backports a fix
from Python 2.5a1, which frees unused arenas, and adds a non-standard
sys._debugmallocstats() function, which prints diagnostic information to
stderr. Finally, when running under Valgrind, the optimized allocator is
deactivated, to allow more convenient debugging of Python memory usage
issues. (BZ#569093)

• The urllib and urllib2 modules ignored the no_proxy variable, which could

lead to programs such as "yum" erroneously accessing a proxy server for
URLs covered by a "no_proxy" exclusion. This update backports fixes of
urllib and urllib2, which respect the "no_proxy" variable, which fixes
these issues. (BZ#549372)

As well, this update adds the following enhancements:

• This update introduces a new python-libs package, subsuming the majority

of the content of the core python package. This makes both 32-bit and
64-bit Python libraries available on PowerPC systems. (BZ#625372)

• The python-libs.i386 package is now available for 64-bit Itanium with the

32-bit Itanium compatibility mode. (BZ#644761)

All Python users are advised to upgrade to these updated packages, which
contain backported patches to correct these issues and add these
enhancements.

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
http://kbase.redhat.com/faq/docs/DOC-11259

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 - 482814 - CVE-2008-5983 python: untrusted python modules search path
• BZ - 541698 - CVE-2009-4134 CVE-2010-1449 CVE-2010-1450 python: rgbimg: multiple security issues
• BZ - 569093 - Python 2.4's arena allocator does not release memory back to the system, leading to "high-water mark" memory usage
• BZ - 590690 - CVE-2010-1634 python: audioop: incorrect integer overflow checks
• BZ - 598197 - CVE-2010-2089 Python: Memory corruption in audioop module
• BZ - 609017 - subprocess leaves open fds on construction error
• BZ - 609020 - subprocess fails in select when descriptors are large
• BZ - 625372 - split python-libs subpackage
• BZ - 644147 - Patch for get_filename in email.message when content-disposition is missing
• BZ - 644761 - python-libs conflict on ia64 compatlayer

CVEs

• CVE-2010-1634
• CVE-2010-1450
• CVE-2009-4134
• CVE-2010-2089
• CVE-2008-5983
• CVE-2010-1449

References

• https://access.redhat.com/security/updates/classification/#low