Bug 491036 (CVE-2009-0846)

Summary: CVE-2009-0846 krb5: ASN.1 decoder can free uninitialized pointer when decoding an invalid encoding (MITKRB5-SA-2009-002)
Product: [Other] Security Response Reporter: Vincent Danen <vdanen>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED ERRATA QA Contact:
Severity: urgent Docs Contact:
Priority: urgent    
Version: unspecifiedCC: jrusnack, kreilly, nalin, rcvalle
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
URL: http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2009-0846
Whiteboard: impact=critical,source=upstream,reported=20090318,public=20090407,cvss2=9.3/AV:N/AC:M/Au:N/C:C/I:C/A:C,cwe=CWE-456->CWE-416
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2009-04-09 05:35:37 EDT Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---
Bug Depends On: 490635, 490636, 491833, 491834, 491835, 491836    
Bug Blocks:    
Attachments:
Description Flags
upstream patch to fix MITKRB5-SA-2009-002 issue (CVE-2009-0846) none

Description Vincent Danen 2009-03-18 22:48:19 EDT
An ASN.1 decoder can free an uninitialized pointer when decoding an
invalid encoding.  This can cause a Kerberos application to crash, or,
under theoretically possible but unlikely circumstances, execute
arbitrary malicious code.  No exploit is known to exist that would
cause arbitrary code execution.

This is an implementation vulnerability in MIT krb5, and is not a
vulnerability in the Kerberos protocol.
Comment 2 Vincent Danen 2009-03-18 22:57:02 EDT
Created attachment 335794 [details]
upstream patch to fix MITKRB5-SA-2009-002 issue (CVE-2009-0846)
Comment 6 Tomas Hoger 2009-03-24 07:46:44 EDT
This flaw can easily allow an attacker to crash affected application.  Code execution depends on ability to exploit free() called on uninitialized pointer.  glibc on Red Hat Enterprise Linux 4 and later provides hardened malloc/free implementations, greatly mitigating possibility of exploitation of this flaw.  Red Hat Enterprise Linux 2.1 and 3 do not offer such hardening, resulting in higher impact rating for those versions.
Comment 7 Tomas Hoger 2009-04-07 14:22:20 EDT
Public now via:
  http://web.mit.edu/kerberos/advisories/MITKRB5-SA-2009-002.txt
Comment 8 errata-xmlrpc 2009-04-07 14:47:43 EDT
This issue has been addressed in following products:

  Red Hat Enterprise Linux 5

Via RHSA-2009:0408 https://rhn.redhat.com/errata/RHSA-2009-0408.html
Comment 9 errata-xmlrpc 2009-04-07 14:47:52 EDT
This issue has been addressed in following products:

  Red Hat Enterprise Linux 4

Via RHSA-2009:0409 https://rhn.redhat.com/errata/RHSA-2009-0409.html
Comment 10 errata-xmlrpc 2009-04-07 14:48:00 EDT
This issue has been addressed in following products:

  Red Hat Enterprise Linux 2.1
  Red Hat Enterprise Linux 3

Via RHSA-2009:0410 https://rhn.redhat.com/errata/RHSA-2009-0410.html
Comment 11 Fedora Update System 2009-04-07 19:23:11 EDT
krb5-1.6.3-16.fc9 has been pushed to the Fedora 9 stable repository.  If problems still persist, please make note of it in this bug report.
Comment 12 Fedora Update System 2009-04-07 19:23:31 EDT
krb5-1.6.3-18.fc10 has been pushed to the Fedora 10 stable repository.  If problems still persist, please make note of it in this bug report.