Bug 1203715 – CVE-2015-1802 libXfont: missing range check in bdfReadProperties

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Bug 1203715 - (CVE-2015-1802) CVE-2015-1802 libXfont: missing range check in bdfReadProperties

Summary:	CVE-2015-1802 libXfont: missing range check in bdfReadProperties

Status:	NEW

Aliases:	CVE-2015-1802

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

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

URL:
Whiteboard:	impact=important,public=20150317,repo...
Keywords:	Security

Depends On:	1203720 1258892 1258893 1258894 1258895
Blocks:	1203722
	Show dependency tree / graph

Reported:	2015-03-19 10:08 EDT by Martin Prpič
Modified:	2018-03-05 14:34 EST (History)
CC List:	4 users (show)

See Also:
Fixed In Version:	libXfont 1.5.1, libXfont 1.4.9
Doc Type:	Bug Fix
Doc Text:	An integer overflow flaw was found in the way libXfont processed certain Glyph Bitmap Distribution Format (BDF) fonts. A malicious, local user could use this flaw to crash the X.Org server or, potentially, execute arbitrary code with the privileges of the X.Org server.
Story Points:	---
Clone Of:
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Last Closed:
Type:	---
Regression:	---
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Documentation:	---
CRM:
Verified Versions:
Category:	---
oVirt Team:	---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---

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Add an attachment (proposed patch, testcase, etc.)

External Trackers
Tracker	ID	Priority	Status	Summary	Last Updated
Red Hat Product Errata	RHSA-2015:1708	normal	SHIPPED_LIVE	Important: libXfont security update	2015-09-03 11:26:36 EDT

Groups: None (edit)

Description Martin Prpič 2015-03-19 10:08:08 EDT

The bdf parser reads a count for the number of properties defined in a font from the font file, and allocates arrays with entries for each property based on that count. It never checked to see if that count was negative, or large enough to overflow when multiplied by the size of the structures being allocated, and could thus allocate the wrong buffer size, leading to out of bounds writes.

A local user could exploit this issue to potentially execute arbitrary code with the privileges of the X.Org server.

Upstream patch:

http://cgit.freedesktop.org/xorg/lib/libXfont/commit/?id=2deda9906480f9c8ae07b8c2a5510cc7e4c59a8e

External References:

http://www.x.org/wiki/Development/Security/Advisory-2015-03-17/

Comment 1 Martin Prpič 2015-03-19 10:14:49 EDT

Created libXfont tracking bugs for this issue:

Affects: fedora-all [bug 1203720]

Comment 2 Fedora Update System 2015-03-23 03:17:11 EDT

libXfont-1.5.1-1.fc21 has been pushed to the Fedora 21 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 4 errata-xmlrpc 2015-09-03 07:26:54 EDT

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7
  Red Hat Enterprise Linux 6

Via RHSA-2015:1708 https://rhn.redhat.com/errata/RHSA-2015-1708.html

Comment 5 ddu 2015-09-07 01:07:38 EDT

Hi guys,

Does this problem CVE affect libXfont shipped with RHEL5?

Best regards,
Dapeng

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