Bug 1203718 (CVE-2015-1803)

Summary:	CVE-2015-1803 libXfont: crash on invalid read in bdfReadCharacters
Product:	[Other] Security Response	Reporter:	Martin Prpič <mprpic>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	btissoir, fonts-bugs, jshort, sandmann, tfrazier
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	libXfont 1.5.1, libXfont 1.4.9	Doc Type:	Bug Fix
Doc Text:	A NULL pointer dereference flaw was discovered 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.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2019-06-08 02:40:09 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1203720, 1258892, 1258893, 1258894, 1258895
Bug Blocks:	1203722

Description Martin Prpič 2015-03-19 14:11:21 UTC

If the bdf parser failed to parse the data for the bitmap for any character, it would proceed with an invalid pointer to the bitmap data and later crash when trying to read the bitmap from that pointer.

A local user could exploit this issue to crash the X.Org server.

Upstream patch:

http://cgit.freedesktop.org/xorg/lib/libXfont/commit/?id=78c2e3d70d29698244f70164428bd2868c0ab34c

External References:

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

Comment 1 Martin Prpič 2015-03-19 14:15:01 UTC

Created libXfont tracking bugs for this issue:

Affects: fedora-all [bug 1203720]

Comment 2 Fedora Update System 2015-03-23 07:17:13 UTC

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 11:26:56 UTC

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 05:07:44 UTC

Hi guys,

Does this problem CVE affect libXfont shipped with RHEL5?

Best regards,
Dapeng

Comment 6 Matt Goldman 2015-09-07 14:08:40 UTC

Dapeng,

Yes, from the whiteboard RHEL 5 is affected:

  rhel-5/libXfont=affected

However, RHEL 5 has entered Production Phase 3 as of January 31, 2014. As per our errata policy:
    
    "During the Production 3 Phase, Critical impact Security Advisories (RHSAs) and selected Urgent Priority Bug Fix Advisories (RHBAs) may be released as they become available."
    Red Hat Enterprise Linux Life Cycle
    https://access.redhat.com/support/policy/updates/errata#Production_3_Phase

This means that Red Hat will not be addressing Low, Moderate, or Important impact CVE's in relation to RHEL 5.

Comment 7 ddu 2015-09-08 05:07:14 UTC

Hi Matt,

Thank you for your comment.

So there is some possibility that this problem will be fixed in rhel5, right?

But we can not guarantee that.

Comment 8 Matt Goldman 2015-09-08 13:06:41 UTC

Dapeng,

Correct. Likely, this will not be fixed in RHEL 5.