July 11, 2007
Symantec Client Security Internet E-mail Auto-Protect Stack Overflow

Revision History
7/16/2007 - Corrected the CVE candidate number


Remote AccessNo
Local AccessYes
Authentication RequiredYes
Exploit publicly availableNo

A stack overflow in Symantec Anti-Virus Corporate Editionís Internet Email Auto-Protect feature could potentially crash the Internet Email scanning feature.

Affected Products
Symantec AntiVirus Corporate Edition 9.x, all builds prior to the solution SAV 9 MR6 (SAV or later
10.0 , all builds Upgrade to version 10.1 or later
Symantec Client Security 2.0.x, all builds prior to the solution Symantec Client Security 2.0.6 MR6 (build 1000-31) or later
3.0.x, all builds Upgrade to SCS 3.1 or later

NOTE: Platinum Support and Premium Support customers can also download the updates from the Platinum Support Web site.

Unaffected Products
Symantec AntiVirus Corporate Edition 10.1 all
10.2 all
Symantec Client Security 3.1 all
Symantec Antivirus for Linux all all
Norton AntiVirus all all
Norton Internet Security all all

Symantec AntiVirus Corporate Editionís Internet E-mail Auto-Protect feature protects incoming and outgoing email messages that use the POP3 or SMTP communications protocol. When Internet E-mail Auto-Protect is enabled, an outgoing email with more than 951 characters in the To:, From: or Subject: fields could cause a stack overflow. The stack overflow could crash the Internet E-mail real-time protection service, resulting in a local denial of service. Subsequent outgoing SMTP email messages will not be scanned if the service has crashed.

File system Auto-Protect (real-time scanning), scheduled scanning, and on-demand scanning are not affected if the Internet E-mail scanning services has stopped, and these features will continue to function.

This issue was reported to Symantec by Jordi Corrales.

Symantec response
Symantec engineers have confirmed that this vulnerability exists in the products listed above, and have provided updates to resolve the issue.

This vulnerability exists only in the Internet E-mail Auto-Protect feature, and it can be exploited only if the feature is enabled on the userís system. The Lotus Notes and Microsoft Exchange Auto-Protect plug-ins are not impacted by this vulnerability.

Symantec is not aware of any customers impacted by this issue, or of any attempts to exploit the issue.

Disable Internet E-Mail Auto-Protect, if the feature is not needed. Administrators can lock this option to ensure that users cannot accidentally re-enable it.

Best Practices
Symantec recommends any affected customers update their product immediately to protect against potential attempts to exploit this vulnerability. As part of normal best practices, Symantec recommends the following:

Symantec would like to thank Jordi Corrales for reporting this issue.

This issue is a candidate for inclusion in the Common Vulnerabilities and Exposures (CVE) list (, which standardizes names for security problems. The CVE initiative has assigned CVE-2007-3771 to this issue

SecurityFocus ( has assigned Bugtraq ID (BID) 24802 to this issue.

Initial Post on: Wednesday, 11-Jul-07 8:00:00
Last modified on: