Bug 722701 (CVE-2011-0226)

Summary:	CVE-2011-0226 freetype: postscript type1 font parsing vulnerability
Product:	[Other] Security Response	Reporter:	Vincent Danen <vdanen>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	CC:	behdad, fonts-bugs, kevin, mkasik
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2015-02-26 23:09:37 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:	723467, 723468, 723469, 889398
Bug Blocks:	722702

Description Vincent Danen 2011-07-16 18:42:34 UTC

The recent exploit for the iPhone is reported [1],[2] to be related to freetype's handling of postscript type1 fonts.  This vulnerability is caused due to an error within the t1_decoder_parse_charstrings() function (src/psaux/t1decode.c) and can be exploited to corrupt memory by tricking a user into processing a specially-crafted postscript type1 font in an application that uses the freetype library.  The report indicates that the vulnerability is in version 2.4.5, but at a quick glance it also looks like 2.3.11 is affected, but not 2.2.x.

Discussion is happening upstream with potential patches being discussed [3].


[1] http://secunia.com/advisories/45167
[2] http://lists.nongnu.org/archive/html/freetype-devel/2011-07/msg00014.html
[3] http://lists.nongnu.org/archive/html/freetype-devel/2011-07/msg00015.html

Comment 1 Huzaifa S. Sidhpurwala 2011-07-18 05:56:05 UTC

This has been assigned CVE-2011-0226:

http://thread.gmane.org/gmane.comp.security.oss.general/5494/focus=5500

Reference:
http://support.apple.com/kb/HT4802

Comment 3 Huzaifa S. Sidhpurwala 2011-07-19 07:16:53 UTC

Following:
http://esec-lab.sogeti.com/post/Analysis-of-the-jailbreakme-v3-font-exploit
i extracted the font from the pdf file

Running the font on ftview or ftbench under valgrind, it seems that there could a possibility of running arbitrary code, packaged as part of the charstings in the font.

=7628== Conditional jump or move depends on uninitialised value(s)
==7628==    at 0x43ED0357: psh_hint_table_activate_mask (pshalgo.c:326)
==7628==    by 0x43ED2D31: ps_hints_apply (pshalgo.c:1730)
==7628==    by 0x43EEF987: t1_decoder_parse_charstrings (t1decode.c:1082)
==7628==    by 0x43EA480B: T1_Parse_Glyph_And_Get_Char_String (t1gload.c:93)
==7628==    by 0x43EA64B6: T1_Load_Glyph (t1gload.c:350)
==7628==    by 0x43E90A82: FT_Load_Glyph (ftobjs.c:683)
==7628==    by 0x8049ADC: test_load (ftbench.c:221)
==7628==    by 0x41D3895C: ???


You would probably need to adjust the payload a bit for linux?

Comment 5 Tomas Hoger 2011-07-19 08:57:11 UTC

Related upstream git commits:
http://git.savannah.gnu.org/cgit/freetype/freetype2.git/commit/?id=c46b1e2476cc1804c0dd25d463be3c99d58befd7
http://git.savannah.gnu.org/cgit/freetype/freetype2.git/commit/?id=dc33b4a1555c184b83a402dfa1856b213e6b4fbd
http://git.savannah.gnu.org/cgit/freetype/freetype2.git/commit/?id=60f8371353013e78ab0a789f49af90d64fe65f0d

Comment 7 Huzaifa S. Sidhpurwala 2011-07-20 09:58:19 UTC

Created freetype tracking bugs for this issue

Affects: fedora-all [bug 723469]

Comment 12 errata-xmlrpc 2011-07-21 15:46:52 UTC

This issue has been addressed in following products:

  Red Hat Enterprise Linux 6

Via RHSA-2011:1085 https://rhn.redhat.com/errata/RHSA-2011-1085.html