Bug 1381865 – CVE-2016-7944 libXfixes: Insufficient validation of server responses results in Integer overflow

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Bug 1381865 - (CVE-2016-7944) CVE-2016-7944 libXfixes: Insufficient validation of server responses results in Integer overflow

Summary:	CVE-2016-7944 libXfixes: Insufficient validation of server responses results ...

Status:	NEW

Aliases:	CVE-2016-7944

Product:	Security Response
Classification:	Other
Component:	vulnerability (Show other bugs)
Sub Component:
Version:	unspecified
Hardware:	All Linux

Priority	medium Severity medium
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Assigned To:	Red Hat Product Security
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Whiteboard:	impact=moderate,public=20160925,repor...
Keywords:	Security

Depends On:	1381866
Blocks:	1381939
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Reported:	2016-10-05 04:45 EDT by Andrej Nemec
Modified:	2017-03-09 19:41 EST (History)
CC List:	4 users (show)

See Also:
Fixed In Version:	libXfixes 5.0.3
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Description Andrej Nemec 2016-10-05 04:45:50 EDT

It was found that when receiving a response from the server protocol data is not validated sufficiently. The 32 bit field "rep.length" is not checked for validity, which allows an integer overflow on 32 bit systems.

A malicious server could send INT_MAX as length, which gets multiplied by the size of XRectangle. In that case the client won't read the whole data from server, getting out of sync.

Upstream patch:

https://cgit.freedesktop.org/xorg/lib/libXfixes/commit/?id=61c1039ee23a2d1de712843bed3480654d7ef42e

External References:

https://lists.x.org/archives/xorg-announce/2016-October/002720.html

CVE assignment:

http://seclists.org/oss-sec/2016/q4/17

Comment 1 Andrej Nemec 2016-10-05 04:46:10 EDT

Created libXfixes tracking bugs for this issue:

Affects: fedora-all [bug 1381866]

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