EMC Legato Networker nsrd.exe DoS Vulnerability

iDefense Security Advisory 01.17.06
http://www.idefense.com/intelligence/vulnerabilities/display.php?id=375
January 17, 2006

I. BACKGROUND

EMC Legato NetWorker is a cross-platform backup and recovery
application.

II. DESCRIPTION

Remote exploitation of a denial of service vulnerability in EMC Corp.'s
Legato Networker allows attackers to crash the nsrd service.

The vulnerability specifically exists due to improper handling of
malformed RPC requests to RPC program number 390109. By sending such a
request, an attacker is able to cause a NULL pointer to be used as the
base in a memory reference, which leads to a crash of the service. The
daemon will crash on a NULL pointer dereference as no exception handlers
are invoked which might allow it to recover.

III. ANALYSIS

Successful exploitation allows a remote attacker to crash the nsrd.exe
process.

IV. DETECTION

iDefense has confirmed this vulnerability in Networker 7.2 build 172.
All previous versions are suspected vulnerable.

V. WORKAROUND

iDefense is currently unaware of any workarounds for this issue.

VI. VENDOR RESPONSE

"Complete resolutions to the vulnerabilities are available today in
NetWorker 7.1.4 and 7.3.  EMC has created a hot-fix to protect against
vulnerabilities for 7.2.1 customers.  No fixes are planned for previous
NetWorker releases."
 
"These remedies are available for download at:"

  http://www.legato.com/support/websupport/product_alerts/011606_NW.htm

VII. CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CAN-2005-3659 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

11/17/2005 Initial vendor notification
11/17/2005 Initial vendor response
01/17/2006 Coordinated public disclosure

IX. CREDIT

Jo Goossens is credited with the discovery of this vulnerability.

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X. LEGAL NOTICES

Copyright © 2006 iDefense, Inc.

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Disclaimer: The information in the advisory is believed to be accurate
at the time of publishing based on currently available information. Use
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