SYM07- 021
August 09, 2007
Symantec ActiveX Control Input Validation Error

Revision History

Risk Impact

Remote AccessYes
Local AccessYes
Authentication RequiredNo
Exploit availableNo

An input validation error in two ActiveX controls used by Norton AntiVirus, Norton Internet Security, and Norton System Works could allow an attacker to execute code on the target system.

Affected Products
Norton AntiVirus 2006 Run LiveUpdate in Interactive Mode
Norton Internet Security 2006 Run LiveUpdate in Interactive Mode
Norton Internet Security, Anti Spyware Edition 2005 Run LiveUpdate in Interactive Mode
Norton System Works 2006 Run LiveUpdate in Interactive Mode

Unaffected Products
Norton 360 All
Norton AntiBot All
Norton AntiVirus 2007 and later
Norton Confidential All
Norton Internet Security 2007 and later
Norton System Works 2007 and later
Symantec AntiVirus Corporate Edition All
Symantec AntiVirus for Linux All
Symantec Client Security All

Symantec was notified that two ActiveX controls supplied by NAVCOMUI.DLL contain an input validation error for two properties of the controls. This error could allow an attacker to crash Internet Explorer, or possibly run arbitrary code with the rights of the logged in user.

Symantec response
Symantec engineers have confirmed that the vulnerability in the products listed in the Affected Products table above. Updates for affected products are available through LiveUpdate.

No versions of Symantec AntiVirus Corporate Edition or Symantec Client Security are affected by this vulnerability.

To successfully exploit this vulnerability, an attacker would need to entice the user to view a specially crafted HTML document. This type of attack is often achieved by sending email containing a link to the malicious site, and persuading the recipient to click on the link.

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

Symantec Security Response has released Bloodhound.Exploit.148 to detect and block attempts to exploit this vulnerability. This detection is available in virus definitions dated 08-09-2007 and later.

In addition, Symantec has released an IPS signature to detect and block attempts to exploit this vulnerability. The signature, HTTP Symantec NAV NavComUI ActiveX BO, is available in signatures dated 08-09-2007 and later.

Virus definitions and IPS signatures are both available through LiveUpdate

How to Obtain the Update
Symantec Norton product users who regularly launch and run LiveUpdate should already have received an updated (non-vulnerable) version of NAVCOMUI.DLL.
However, to ensure all available updates have been applied, users can manually launch and run LiveUpdate in Interactive mode as follows:

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 Carsten Eiram, Secunia Research for reporting this issue and coordinating with us on the response.

The Common Vulnerabilities and Exposures (CVE) initiative has assigned CVE Candidate CVE-2007-2955 to this issue.
This issue is a candidate for inclusion in the CVE list (, which standardizes names for security problems.

SecurityFocus ( has assigned Bugtraq ID (BID) 24983 to this issue

Initial Post on: Thursday, 09-Aug-07 08:42:00
Last modified on: