[New-bugs-announce] [issue14234] CVE-2012-0876 (hash table collisions CPU usage DoS) for embedded copy of expat

[Dave Malcolm]

New submission from Dave Malcolm <dmalcolm at redhat.com>:

Expat 2.1.0 Beta was recently announced:
  http://mail.libexpat.org/pipermail/expat-discuss/2012-March/002768.html
which contains (among other things) a fix for a hash-collision denial-of-service attack (CVE-2012-0876)

I'm attaching a patch which minimally backports the hash-collision fix part of expat 2.1.0 to the embedded copy of expat in the CPython source tree, and which adds a call to XML_SetHashSalt() to pyexpat when creating parsers.  It reuses part of the hash secret from Py_HashSecret.

----------
components: XML
files: expat-hash-randomization.patch
keywords: patch
messages: 155198
nosy: dmalcolm
priority: normal
severity: normal
status: open
title: CVE-2012-0876 (hash table collisions CPU usage DoS) for embedded copy of expat
versions: Python 2.6, Python 2.7, Python 3.1, Python 3.2, Python 3.3, Python 3.4
Added file: http://bugs.python.org/file24762/expat-hash-randomization.patch

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