[issue19279] UTF-7 to UTF-8 decoding crash

[Serhiy Storchaka]

Serhiy Storchaka added the comment:

Here is a patch for 3.3+.

Other versions are affected too. They don't raise SystemError, but produce illegal unicode string on wide build.

E.g. in Python 2.7:

>>> 'a+/,+IKw-b'.decode('utf-7', 'replace')
u'a\ufffd\U003f20acb'

\U003f20ac is illegal code.

As encoding and encoded data can come from external source, this can be used in secure attacks.

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keywords: +patch
nosy: +barry, benjamin.peterson, georg.brandl, larry
priority: normal -> release blocker
stage: needs patch -> patch review
type: crash -> security
versions: +Python 2.6, Python 2.7, Python 3.2
Added file: http://bugs.python.org/file32156/utf7_errors.patch

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue19279>
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