Bug 1519082 – CVE-2017-16611 libXfont: User can trigger arbitrary file read by X server causing a DoS

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Bug 1519082 - (CVE-2017-16611) CVE-2017-16611 libXfont: User can trigger arbitrary file read by X server causing a DoS

Summary:	CVE-2017-16611 libXfont: User can trigger arbitrary file read by X server cau...

Status:	CLOSED WONTFIX

Aliases:	CVE-2017-16611

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

Priority	low Severity low
Target Milestone:	---
Target Release:	---
Assigned To:	Red Hat Product Security
QA Contact:
Docs Contact:

URL:
Whiteboard:	impact=low,public=20171125,reported=2...
Keywords:	Security

Depends On:	1519083 1519084
Blocks:	1519085
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Reported:	2017-11-30 00:42 EST by Sam Fowler
Modified:	2017-11-30 23:30 EST (History)
CC List:	10 users (show)

See Also:
Fixed In Version:	libXfont 1.5.4, libXfont2 2.0.3
Doc Type:	If docs needed, set a value
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Last Closed:	2017-11-30 23:30:53 EST
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Regression:	---
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oVirt Team:	---
RHEL 7.3 requirements from Atomic Host:
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Description Sam Fowler 2017-11-30 00:42:54 EST

A low privileged user can create symlinks to trigger arbitrary file reads by X server. Under certain configurations, a user can create a symlink to special files (e.g. /dev/watchdog) to cause a denial of service.

A non-privileged X client can instruct X server running under root to open any file by creating a directory with symlinks(s) named "fonts.dir", "fonts.alias" or any font file to link to any other file in the system. X server will follow the symlink and open and read the file. When opened and under certain configurations, special files like /dev/watchdog can trigger system operations (e.g. reboot).

References:
http://openwall.com/lists/oss-security/2017/11/28/7
https://cgit.freedesktop.org/xorg/lib/libXfont/commit/?h=libXfont-1.5-branch&id=5ed8ac0e4f063825b8ecda48e9a111d3ce92e825
https://cgit.freedesktop.org/xorg/lib/libXfont/commit/?id=7b377456f95d2ec3ead40f4fb74ea620191f88c8

Comment 1 Sam Fowler 2017-11-30 00:43:16 EST

Created libXfont tracking bugs for this issue:

Affects: fedora-all [bug 1519084]


Created libXfont2 tracking bugs for this issue:

Affects: fedora-all [bug 1519083]

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