iDefense Security Advisory 07.09.08: Novell eDirectory LDAP Search Request Heap Corruption Vulnerability

iDefense Security Advisory 07.09.08
http://labs.idefense.com/intelligence/vulnerabilities/
Jul 09, 2008

I. BACKGROUND

Novell eDirectory is cross-platform directory server that implements the
Lightweight Directory Access Protocol (LDAP). The search request is used
to search a directory tree for objects that match a search filter. For
more information, see the vendor's site found at the following URL.

http://www.novell.com/products/edirectory/

II. DESCRIPTION

Remote exploitation of a heap buffer overflow vulnerability in Novell
Inc.'s eDirectory could allow an attacker to execute arbitrary code
with the privileges of the affected service.

The vulnerability exists due to an incorrect calculation when allocating
a heap buffer to store the search parameters. By passing NULL search
parameters, it is possible to overflow a heap based buffer with the
string "(null)". This can result in the corruption of heap management
structures, and depending on the layout of the heap, possibly function
pointers.

III. ANALYSIS

Exploitation of this vulnerability results in the execution of arbitrary
code with the privileges of the affected service, usually root. Since
the data that overflows the buffer is not controlled by the attacker,
exploitation is non-trivial.

IV. DETECTION

iDefense has confirmed the existence of this vulnerability in eDirectory
version 8.8 SP2 for Linux. Other versions may also be affected.

V. WORKAROUND

It is possible to disable the LDAP service from running via the
ndsmodules.conf file which is usually located in
/etc/opt/novell/eDirectory/conf. However, doing so greatly reduces the
functionality of this software.

VI. VENDOR RESPONSE

Novell Inc. has addressed this vulnerability with the release of FTF2
for eDirectory 8.8 SP2 (8.8.2) and SP10b for eDirectory 8.7.3. For more
information visit the following URL.

http://www.novell.com/support/viewContent.do?externalId=3843876

VII. CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CVE-2008-1809 to this issue. This is a candidate for inclusion in
the CVE list (http://cve.mitre.org/), which standardizes names for
security problems.

VIII. DISCLOSURE TIMELINE

03/10/2008 Initial vendor notification
03/13/2008 Initial vendor response
07/09/2008 Coordinated public disclosure

IX. CREDIT

The discoverer of this vulnerability wishes to remain anonymous.

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X. LEGAL NOTICES

Copyright © 2008 iDefense, Inc.

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at the time of publishing based on currently available information. Use
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