(RHSA-2011:0027) Low: python security, bug fix, and enhancement update

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.