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: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED NOTABUG QA Contact:
Severity: low Docs Contact:
Priority: low    
Version: unspecifiedCC: 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:
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.