CA ARCserve Backup for Laptops and Desktops Authentication Bypass
Vulnerability

iDefense Security Advisory 09.20.07
http://labs.idefense.com/intelligence/vulnerabilities/
Sep 20, 2007

I. BACKGROUND

ARCServe Backup for Laptops and Desktops is a version of ARCServe Backup
targeted at small to medium sized businesses, with many mobile/remote
users. It provides client agents that detect network connectivity and
commit backup data when it is found. For more information, consult the
product home page at the following URL.

http://www3.ca.com/solutions/Product.aspx?ID=263

II. DESCRIPTION

Remote exploitation of an authentication bypass vulnerability in
Computer Associates Inc.'s ARCServe Backup for Laptops and Desktops
allows attackers to execute arbitrary code with SYSTEM privileges.

This vulnerability specifically exists since the command handlers that
service network requests do not check to see if the peer is
authenticated.

III. ANALYSIS

Exploitation of this vulnerability allows an attacker to execute all
commands granted to the server administrator. An attacker can add and
delete users and entire organizations, and initiate restore operations
for clients that connect to the server.

Using this vulnerability, an attacker is able to upload arbitrary files
to the server. This results in the execution of arbitrary code with
SYSTEM privileges.

IV. DETECTION

iDefense has confirmed the existence of this vulnerability in ARCServe
Backup for Laptops and Desktops version R11.1 Build 900. Other versions
may also be affected.

V. WORKAROUND

iDefense is currently unaware of any workarounds for this issue.

VI. VENDOR RESPONSE

Computer Associates has addressed this vulnerability with an update. For
more information consult CA's security notice at the following URL.

http://supportconnectw.ca.com/public/sams/lifeguard/infodocs/caarcservebld-securitynotice.asp

VII. CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CVE-2007-5006 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

03/06/2007  Initial vendor notification
03/06/2007  Initial vendor response
09/20/2007  Coordinated public disclosure

IX. CREDIT

The discoverer of this vulnerability wishes to remain anonymous.

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X. LEGAL NOTICES

Copyright © 2007 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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