[Python-checkins] bpo-36384: [doc] Mention CVE-2021-29921 fix in 3.8.12 (GH-27824) (GH-27827)

[ambv]

https://github.com/python/cpython/commit/98820250a3c9c131d3c2d57c4fc5260aebd8aa1d
commit: 98820250a3c9c131d3c2d57c4fc5260aebd8aa1d
branch: 3.9
author: Miss Islington (bot) <31488909+miss-islington at users.noreply.github.com>
committer: ambv <lukasz at langa.pl>
date: 2021-08-19T11:20:47+02:00
summary:

bpo-36384: [doc] Mention CVE-2021-29921 fix in 3.8.12 (GH-27824) (GH-27827)

(cherry picked from commit 0fd66e46b2f472d0d206a185dc8892f4f0347cb6)

Co-authored-by: Łukasz Langa <lukasz at langa.pl>

files:
M Doc/library/ipaddress.rst
M Doc/whatsnew/3.8.rst

diff --git a/Doc/library/ipaddress.rst b/Doc/library/ipaddress.rst
index 1c2263b128a8fe..2ab4dd83ad4dee 100644
--- a/Doc/library/ipaddress.rst
+++ b/Doc/library/ipaddress.rst
@@ -132,6 +132,11 @@ write code that handles both IP versions correctly.  Address objects are
       The above change was also included in Python 3.9 starting with
       version 3.9.5.
 
+   .. versionchanged:: 3.8.12
+
+      The above change was also included in Python 3.8 starting with
+      version 3.8.12.
+
    .. attribute:: version
 
       The appropriate version number: ``4`` for IPv4, ``6`` for IPv6.
diff --git a/Doc/whatsnew/3.8.rst b/Doc/whatsnew/3.8.rst
index dbc3875aae61b3..1b3bb152eea13c 100644
--- a/Doc/whatsnew/3.8.rst
+++ b/Doc/whatsnew/3.8.rst
@@ -2247,3 +2247,16 @@ separator key, with ``&`` as the default.  This change also affects
 functions internally. For more details, please see their respective
 documentation.
 (Contributed by Adam Goldschmidt, Senthil Kumaran and Ken Jin in :issue:`42967`.)
+
+Notable changes in Python 3.8.12
+================================
+
+Starting with Python 3.8.12 the :mod:`ipaddress` module no longer accepts
+any leading zeros in IPv4 address strings. Leading zeros are ambiguous and
+interpreted as octal notation by some libraries. For example the legacy
+function :func:`socket.inet_aton` treats leading zeros as octal notation.
+glibc implementation of modern :func:`~socket.inet_pton` does not accept
+any leading zeros.
+
+(Originally contributed by Christian Heimes in :issue:`36384`, and backported
+to 3.8 by Achraf Merzouki.)