Vulnerability Note VU#374121

MIT Kerberos contains array overrun in RPC library used by kadmind

Original Release date: 18 Mar 2008 | Last revised: 22 Jul 2011

Overview

Vulnerabilities in the MIT Kerberos libgssrpc library may allow an attacker to cause a denial of service or potentially execute arbitrary code.

Description

The MIT krb5 Kerberos implementation includes a GSS RPC library used in the Kerberos administration server (kadmind). Two flaws exist in the libgssprc library that can cause an array overrun if too many file descriptors are opened. These flaws result in a vulnerability that could allow memory corruption in the kadmind server.

MIT notes that in software versions 1.4 and later, this flaw can only be exploited in configurations that allow large numbers of open file descriptors in a process. In software versions before 1.3, a similar flaw can be exploited in similar circumstances but is further limited to platforms that do not define certain macros in certain C system header files.

Impact

An unauthenticated remote attacker can cause memory corruption in the libgssrpc library used by kadmind. kadmind will crash, thereby resulting in a denial of service. MIT notes that it is at least theoretically possible for such corruption to result in database corruption or arbitrary code execution.

Solution

Upgrade or apply a patch from the vendor
Patches have been released to address these issues. Please see the Systems Affected section of this document for more details.


Workaround

Before starting kadmind, use "ulimit -n" for Bourne shell and derivatives or "limit descriptors" for C shell and derivatives. Or use similar resource-limiting mechanisms in the invoking process to limit the maximum open file descriptors. The chosen limit should be less than or equal to the value of the FD_SETSIZE macro typically defined in the <sys/select.h> header file.

Systems Affected (Learn More)

VendorStatusDate NotifiedDate Updated
MIT Kerberos Development TeamAffected06 Mar 200818 Mar 2008
UbuntuAffected06 Mar 200819 Mar 2008
Cisco Systems, Inc.Not Affected06 Mar 200810 Mar 2008
Computer AssociatesNot Affected06 Mar 200818 Mar 2008
Force10 Networks, Inc.Not Affected06 Mar 200822 Jul 2011
Intel CorporationNot Affected06 Mar 200806 Mar 2008
IntotoNot Affected06 Mar 200806 Mar 2008
Juniper Networks, Inc.Not Affected06 Mar 200803 Apr 2008
Microsoft CorporationNot Affected06 Mar 200803 Apr 2008
Secure Computing Network Security DivisionNot Affected06 Mar 200806 Mar 2008
Sun Microsystems, Inc.Not Affected06 Mar 200818 Mar 2008
TippingPoint, Technologies, Inc.Not Affected06 Mar 200818 Mar 2008
3com, Inc.Unknown06 Mar 200806 Mar 2008
AlcatelUnknown06 Mar 200806 Mar 2008
Apple Computer, Inc.Unknown06 Mar 200806 Mar 2008
If you are a vendor and your product is affected, let us know.View More »

CVSS Metrics (Learn More)

Group Score Vector
Base N/A N/A
Temporal N/A N/A
Environmental N/A N/A

References

Credit

Thanks to Ken Raeburn of the MIT Kerberos Team for reporting this vulnerability. MIT credits Jeff Altman of Secure Endpoints with discovering and reporting this issue in software version 1.6.3 and the Red Hat Security Response Team for reporting relevant information about older versions of the software.

This document was written by Chad R Dougherty.

Other Information

  • CVE IDs: CVE-2008-0947 CVE-2008-0948
  • Date Public: 18 Mar 2008
  • Date First Published: 18 Mar 2008
  • Date Last Updated: 22 Jul 2011
  • Severity Metric: 2.87
  • Document Revision: 16

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