Symantec Backup Exec RPC Remote Heap Overflow Vulnerability

iDefense Security Advisory 07.11.07
http://labs.idefense.com/intelligence/vulnerabilities/ 
Jul 11, 2007

I. BACKGROUND

Symantec Backup Exec is a data recovery solution. It provides backup
services and includes agents that provide protection and recovery.
Additionally, it facilitates management of local and remote server
backups. More information is available at the URL shown below.

http://www.symantec.com/smb/products/overview.jsp?pcid=bu_rec&pvid=bewin_svr 

II. DESCRIPTION

Remote exploitation of a heap overflow vulnerability in Symantec Backup
Exec could allow an unauthenticated attacker to create a denial of
service condition or potentially execute arbitrary code.

The flaw specifically exists within the RPC server that listens on TCP
port 6106. When handling requests using the "ncacn_ip_tcp" protocol,
the service will copy a user supplied amount of data into a fixed-size
heap buffer.

III. ANALYSIS

Exploitation allows attackers to cause the affected service to
terminate. This vulnerability has the potential to lead to the
execution of arbitrary code.

No authentication is required to access the affected RPC service. An
attacker only needs the ability to establish a TCP session.

IV. DETECTION

iDefense confirmed the existence of this vulnerability in Symantec
Backup Exec 10d with all current hot-fixes and service packs applied.
Other versions are suspected to be vulnerable.

V. WORKAROUND

Employing firewalls to limit access to the affected service will
mitigate exposure to this vulnerability.

VI. VENDOR RESPONSE

Symantec has addressed this vulnerability by releasing a HotFix. More
information is available in Symantec's advisory at the following URL.

http://securityresponse.symantec.com/avcenter/security/Content/2007.07.11a.html 

VII. CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CVE-2007-3509 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

05/01/2007  Initial vendor notification
05/01/2007  Initial vendor response
07/11/2007  Coordinated public disclosure

IX. CREDIT

The discoverer of this vulnerability wishes to remain anonymous.

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X. LEGAL NOTICES

Copyright =C2=A9 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
of the information constitutes acceptance for use in an AS IS condition.
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