[New-bugs-announce] [issue44394] [security] CVE-2013-0340 "Billion Laughs" fixed in Expat >=2.4.0: Updated to vendoed copy to expat 2.4.1

[STINNER Victor]

New submission from STINNER Victor <vstinner at python.org>:

Our vendored copy of Modules/expat/ should be updated to Expat 2.4.1 to retrieve the fix for the security vulnerabily CVE-2013-0340 "Billion Laughs":
https://blog.hartwork.org/posts/cve-2013-0340-billion-laughs-fixed-in-expat-2-4-0/

The table of vulnerabilities in Python XML parsers should be updated as well:
https://docs.python.org/dev/library/xml.html#xml-vulnerabilities

My outdated notes on Modules/expat/: copy of libexpat

* ./configure --with-system-expat
* Rationale: https://mail.python.org/pipermail/python-dev/2017-June/148287.html
* Used on Windows and macOS, Linux distributions use system libexpat
* Version: search for XML_MAJOR_VERSION in Modules/expat/expat.h
* Script to update it: see attached script to https://bugs.python.org/issue30947
* Recent update: https://bugs.python.org/issue30947
* Python 2.7, 3.3-3.6 use libexpat 2.2.1

https://pythondev.readthedocs.io/files.html

----------
components: Extension Modules
messages: 395634
nosy: vstinner
priority: normal
severity: normal
status: open
title: [security] CVE-2013-0340 "Billion Laughs" fixed in Expat >=2.4.0: Updated to vendoed copy to expat 2.4.1
type: security
versions: Python 3.10, Python 3.11, Python 3.6, Python 3.7, Python 3.8, Python 3.9

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