Symantec AntiVirus Scan Engine Web Service Buffer Overflow Vulnerability

iDEFENSE Security Advisory 10.04.05
http://www.idefense.com/application/...ulnerabilities
October 4, 2005

I. BACKGROUND

Symantec Scan Engine is a TCP/IP server and programming interface that=20
enables third parties to incorporate support for Symantec content=20
scanning technologies into their proprietary applications. More=20
information is available from the vendor website:=20

http://enterprisesecurity.symantec.c...?productid=3D=
1
73

II. DESCRIPTION

Remote exploitation of a buffer overflow vulnerability in Symantec=20
AntiVirus Scan Engine can allow remote attackers to execute arbitrary=20
code.=20

The vulnerability specifically exists due to insufficient input=20
validation of HTTP Headers. A remote attacker can send a specially=20
crafted HTTP request to the administrative Scan Engine Web Wervice on=20
port 8004 to crash the service or execute arbitrary code. Due to=20
improper use of signed integer value types, a negative value can be=20
supplied by a connecting client, which will interpret the value as a=20
very large number and later use the value as an argument to a memory=20
copy operation. An overly long copy will occur resulting in a heap=20
overflow. Remote attackers can supply carefully crafted HTTP requests=20
to trigger the heap overflow and execute arbitrary code.

III. ANALYSIS

Successful exploitation of the vulnerability can result in remote code=20
execution with SYSTEM privileges. Exploitation of the vulnerability=20
does not require credentials or any other element in the attack other=20
than being able to send a HTTP request to TCP port 8001 on the=20
vulnerable server. It is recommended to apply the vendor-supplied=20
workaround or upgrade to the latest available version of the software.=20

IV. DETECTION

iDEFENSE Labs has confirmed the existence of this vulnerability in=20
Symantec AntiVirus Scan Engine 4.0. The vendor has confirmed that the=20
vulnerability also effects products utilizing Symantec AntiVirus Scan=20
Engine 4.3, however Scan Engine 4.1 is not affected.

V. WORKAROUND

The vendor has supplied the following workaround solution:

"Default installation instructions state that, for security reasons,=20
customers should access the administrative interface using a switch or=20
via a secure segment of the network. The Symantec AntiVirus Scan Engine=20
Administration default port, 8004/tcp, should be locked down for=20
trusted internal access only. This port can be changed, as it might=20
conflict with existing applications in the environment. But whatever=20
port is used for the user-interface, it should never be visible=20
external to the network which greatly reduces opportunities for=20
unauthorized access. A customer may choose to completely disable the=20
Symantec AntiVirus Scan Engine's user-interface once it has been=20
satisfactorily configured.

* To disable the user interface, set the port to "0" in the user-
interface and restart the Symantec AntiVirus Scan Engine.=20

* To re-enable the user-interface, edit the Symantec AntiVirus Scan=20
Engine configuration file, set the port back to 8004/tcp, or the=20
applicable user-configured port, and restart the Symantec AntiVirus=20
Scan Engine."

VI. VENDOR RESPONSE

"Symantec Engineers have verified this issue and made security updates
available for the Symantec AntiVirus Scan Engine. Symantec strongly
recommends all customers immediately apply the latest updates for their
supported product versions to protect against these types of threats.
Symantec is unaware of any adverse customer impact from this issue."

A vendor advisory for this issue is available at:

http://www.symantec.com/avcenter/sec...005.10.04.html

VII. CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CAN-2005-2758 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

08/31/2005 Initial vendor notification
08/31/2005 Initial vendor response
10/04/2005 Coordinated public disclosure

IX. CREDIT

The discoverer of this vulnerability wishes to remain anonymous.

infamous41md[at]hotpop.com is credited with this discovery.

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X. LEGAL NOTICES

Copyright (c) 2005 iDEFENSE, Inc.

Permission is granted for the redistribution of this alert
electronically. It may not be edited in any way without the express
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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.
There are no warranties with regard to this information. Neither the
author nor the publisher accepts any liability for any direct, indirect,
or consequential loss or damage arising from use of, or reliance on,
this information.