Bug 1168051 (CVE-2014-9087)

Summary:	CVE-2014-9087 libksba: integer underflow flaw leading to a heap-based buffer overflow in ksba_oid_to_str()
Product:	[Other] Security Response	Reporter:	Murray McAllister <mmcallis>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED WONTFIX	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	carnil, rdieter, sisharma, tmraz
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	libksba 1.3.2	Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2015-10-09 12:05:31 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:	1168052
Bug Blocks:	1168053

Description Murray McAllister 2014-11-26 00:44:31 UTC

An integer underflow flaw, leading to a heap-based buffer overflow, was found in the ksba_oid_to_str() function of the libksba library, used by various GnuPG utilities. Specially-crafted S/MIME messages or ECC-based OpenPGP data could cause an application using libksba to crash or, potentially, execute arbitrary code.

Upstream patch:
http://git.gnupg.org/cgi-bin/gitweb.cgi?p=libksba.git;a=commit;h=f715b9e156dfa99ae829fc694e5a0abd23ef97d7

References:
http://seclists.org/oss-sec/2014/q4/788
http://lists.gnupg.org/pipermail/gnupg-announce/2014q4/000359.html

Comment 1 Murray McAllister 2014-11-26 00:45:15 UTC

Created libksba tracking bugs for this issue:

Affects: fedora-all [bug 1168052]

Comment 3 Murray McAllister 2014-11-26 00:52:09 UTC

This issue has been addressed in upstream version 1.3.2.

Comment 4 Martin Prpič 2014-11-26 10:11:15 UTC

MITRE assigned CVE-2014-9087 to this issue:

http://seclists.org/oss-sec/2014/q4/801

Comment 5 Fedora Update System 2014-12-06 02:34:06 UTC

libksba-1.3.2-1.fc20 has been pushed to the Fedora 20 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 6 Fedora Update System 2014-12-06 10:32:37 UTC

libksba-1.3.2-1.fc21 has been pushed to the Fedora 21 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 7 Fedora Update System 2014-12-07 04:38:47 UTC

libksba-1.3.2-1.fc19 has been pushed to the Fedora 19 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 9 Siddharth Sharma 2015-10-09 11:17:59 UTC

Analysis:

libksba is library used to create X.509 Certificates, version of libksba as shipped in RHEL is affected by this flaw. Following is the problematic code in function

char *
ksba_oid_to_str (const char *buffer, size_t length)
{
 char *string, *p;

 unsigned long val, valmask;  // val is unsigned long

 ...

/* so just before next line if value of 'val is less than 80, it would subtract val - 80, resulting in very large value which would not fit in the buffer used in 
sprintf function causing crash. */

     val -= 80;
     sprintf (p, "2.%lu", val);


There is no evidence of this being exploited in wild.