Bug 1191078 (CVE-2014-9656)

Summary:	CVE-2014-9656 freetype: integer underflow in the tt_sbit_decoder_load_image()
Product:	[Other] Security Response	Reporter:	Vasyl Kaigorodov <vkaigoro>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED NOTABUG	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	behdad, fonts-bugs, kevin, mkasik
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	freetype 2.5.4	Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2015-02-19 15:33:13 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:	1191099
Bug Blocks:	1191102

Description Vasyl Kaigorodov 2015-02-10 12:49:56 UTC

Common Vulnerabilities and Exposures assigned CVE-2014-9656 to the following issue:

The tt_sbit_decoder_load_image function in sfnt/ttsbit.c in FreeType before
2.5.4 does not properly check for an integer overflow, which allows remote
attackers to cause a denial of service (out-of-bounds read) or possibly have
unspecified other impact via a crafted OpenType font.

http://code.google.com/p/google-security-research/issues/detail?id=196
http://git.savannah.gnu.org/cgit/freetype/freetype2.git/commit/?id=f0292bb9920aa1dbfed5f53861e7c7a89b35833a

Comment 1 Vasyl Kaigorodov 2015-02-10 12:55:03 UTC

Created freetype tracking bugs for this issue:

Affects: fedora-all [bug 1191099]

Comment 2 Tomas Hoger 2015-02-19 15:29:39 UTC

Upstream bug is:

https://savannah.nongnu.org/bugs/?43680

Issue was fixed upstream in 2.5.4.

This is an integer underflow issue in an integer overflow check, which guards against buffer over-read.  This can easily trigger crash.

The problem was introduced in the following commit:

http://git.savannah.gnu.org/cgit/freetype/freetype2.git/commit/?id=ba931be2

Additionally, prior to upstream version 2.5, affected code was only built and used when FT_CONFIG_OPTION_OLD_INTERNALS macro was not defined.  It was defined by default in upstream versions prior to 2.4.12:

http://git.savannah.gnu.org/cgit/freetype/freetype2.git/commit/?id=e4ecce3b

The freetype packages in Red Hat Enterprise Linux are based on older upstream versions and do not override this upstream setting, i.e. they define FT_CONFIG_OPTION_OLD_INTERNALS.  Therefore, they were not affected by this issue, or the problem commit e4ecce3b attempted to address.

Statement:

This issue did not affect the versions of freetype as shipped with Red Hat Enterprise Linux 5, 6, and 7.