Bug 245547 (CVE-2007-2442)

Summary:	CVE-2007-2442 krb5 RPC library unitialized pointer free
Product:	[Other] Security Response	Reporter:	Mark J. Cox <mjc>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	Keywords:	Security
Target Milestone:	---
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2008-02-26 15:15:04 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:	239073, 245544
Bug Blocks:

Description Mark J. Cox 2007-06-25 11:37:15 UTC

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 2007-06-25 11:39:10 UTC

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 18:20:33 UTC

Lifting embargo: http://web.mit.edu/Kerberos/advisories/MITKRB5-SA-2007-004.txt

Comment 4 Red Hat Product Security 2008-02-26 15:15:04 UTC

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