Public Vulnerability Reports

EMC Legato Networker nsrexecd.exe Heap Overflow Vulnerability



EMC Legato NetWorker is a cross-platform backup and recovery


Remote exploitation of a heap overflow vulnerability in EMC Corp.'s
Legato Networker allows attackers to execute arbitary code on windows

The vulnerability specifically exists due to improper handling of
malformed RPC requests to RPC program number 390113. When such a request
is sent by an attacker, it is possible to overwrite portions of heap
memory, thus leading to arbitrary code execution by way of a function
pointer overwrite. If an attacker can populate memory so that his data
is in a predictable location, arbitrary code execution is possible. It
is possible to populate memory in several ways, including by utilizing
memory leaks.


Successful exploitation allows a remote attacker to gain access to a
targetted machine. As nsrd.exe is installed on backup client machines
as well as server machines, an attacker may rapidly compromise a
network using this vulnerability.


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


iDefense is currently unaware of any workarounds for this issue.


"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:"


The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CAN-2005-3658 to this issue. This is a candidate for inclusion in
the CVE list (, which standardizes names for
security problems.


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


Jo Goossens is credited with the discovery of this vulnerability.

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Copyright © 2006 Verisign, Inc.

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