Public Vulnerability Reports

Veritas Backup Exec Agent Browser Registration Request Buffer Overflow Vulnerability



Backup Exec is a next generation backup and restore solution for
Microsoft Windows server environments. More information is available


Remote exploitation of a stack-based buffer overflow vulnerability in
Veritas Backup Exec allows attackers to execute arbitrary code.

The vulnerability specifically exists within the function responsible
for receiving and parsing registration requests. The registration
request packet contains the hostname and connecting TCP port of the
client which is stored in an array on the stack. An attacker can send a
registration request with an overly long hostname value to overflow the
array and take control of the saved return address to execute arbitrary


Successful exploitation does not require authentication thereby allowing
any remote attacker to execute arbitrary code under the privileges of
the Backup Exec Agent Browser (benetns.exe) process which is usually a
domain administrative account.


iDEFENSE has confirmed the existence of this vulnerability in Backup
Exec for Windows Servers 9.1.


Use a firewall to restrict incoming connections to trusted workstations
running the Backup Exec client software.


8.60.3878 Hotfix 68 - Backup Exec
(Buffer overflow creates a security hole in Agent Browser)

9.1.4691 Hotfix 40 - Backup Exec
(Buffer overflow creates a security hole in Agent Browser;
Licensed Storage Central becomes Eval when Backup Exec 9.1 is uninstalled)
*Requires Backup Exec 9.1.4691 Service Pack 1


The Common Vulnerabilities and Exposures (CVE) project has assigned the
names CAN-2004-1172 to these issues. This is a candidate for inclusion
in the CVE list (, which standardizes names for
security problems.


11/02/2004    Initial vendor contact
12/16/2004    Initial vendor response
12/16/2004    Public disclosure


An anonymous contributor and Patrik Karlsson ( are
credited with discovering this vulnerability.

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Copyright © 2004 Verisign, Inc.

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