Bug 1381928 – CVE-2016-7950 libXrender: Insufficient validation of server responses results out-of-bounds write in XRenderQueryFilters

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Bug 1381928 - (CVE-2016-7950) CVE-2016-7950 libXrender: Insufficient validation of server responses results out-of-bounds write in XRenderQueryFilters

Summary:	CVE-2016-7950 libXrender: Insufficient validation of server responses results...

Status:	NEW

Aliases:	CVE-2016-7950

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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URL:
Whiteboard:	impact=moderate,public=20160925,repor...
Keywords:	Security

Depends On:	1381930
Blocks:	1381939
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Reported:	2016-10-05 07:34 EDT by Andrej Nemec
Modified:	2017-03-09 19:40 EST (History)
CC List:	4 users (show)

See Also:
Fixed In Version:	libXrender 0.9.10
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Description Andrej Nemec 2016-10-05 07:34:23 EDT

It was found that when receiving a response from the server protocol data is not validated sufficiently. The memory for filter names is reserved right after receiving the reply. After that, filters are iterated and each individual filter name is stored in that reserved memory. The individual name lengths are not checked for validity, which means that a malicious server can reserve less memory than it will write to during each iteration.

Upstream patch:

https://cgit.freedesktop.org/xorg/lib/libXrender/commit/?id=8fad00b0b647ee662ce4737ca15be033b7a21714

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 07:35:02 EDT

Created libXrender tracking bugs for this issue:

Affects: fedora-all [bug 1381930]

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