Bug 245547 (CVE-2007-2442)

Summary: CVE-2007-2442 krb5 RPC library unitialized pointer free
Product: [Other] Security Response Reporter: Mark J. Cox (Product Security) <mjc>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED ERRATA QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedKeywords: Security
Target Milestone: ---   
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard: impact=important,reported=20070503,public=20070626,source=mit
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2008-02-26 10:15:04 EST Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Bug Depends On: 239073, 245544    
Bug Blocks:    

Description Mark J. Cox (Product Security) 2007-06-25 07:37:15 EDT
The MIT Kerberos Team has made us aware of the following issue:

CVE-2007-2442: The RPC library can free an uninitialized pointer.

"CVE-2007-2442: The function gssrpc__svcauth_gssapi() in
src/lib/rpc/svc_auth_gssapi.c declares an automatic variable "creds"
of type auth_gssapi_creds.  This type includes a gss_buffer_desc
(which includes a pointer to void used as a pointer to a buffer of
bytes).  If gssrpc__svcauth_gssapi() receives an RPC credential with a
length of zero, it jumps to the label "error", which executes some
cleanup code.  At this point, the gss_buffer_desc in "creds" is not
yet initialized, and the cleanup code calls xdr_free() on "creds",
which then attempts to free the memory pointed to by the uninitialized
"value" member of the gss_buffer_desc.

Exploitation of freeing of invalid pointers is believed to be
difficult, and depends on a variety of factors specific to a given
malloc implementation."

This issue is embargoed until 20070626
Comment 1 Mark J. Cox (Product Security) 2007-06-25 07:39:10 EDT
For Red Hat Enterprise Linux 4 and 5, glibc contains checks that prevent this
issue from being exploitable.  Therefore this is a denial of service issue and
is impact important.

For Red Hat Enterprise Linux 2.1 and 3, this issue is potentially exploitable
and could result in arbitrary code execution.  Therefore this is is impact critical.
Comment 3 Josh Bressers 2007-06-26 14:20:33 EDT
Lifting embargo: http://web.mit.edu/Kerberos/advisories/MITKRB5-SA-2007-004.txt
Comment 4 Red Hat Product Security 2008-02-26 10:15:04 EST
This issue was addressed in:

Red Hat Enterprise Linux:
  http://rhn.redhat.com/errata/RHSA-2007-0384.html
  http://rhn.redhat.com/errata/RHSA-2007-0562.html

Fedora:
  https://admin.fedoraproject.org/updates/F7/FEDORA-2007-0740