[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
CSIRTUK ADVISORY - 3426 - Kaspersky - Web Scanner ActiveX Format String Vulnerability
CSIRTUK ADVISORY - 3426 dated 11.10.07 time 11:28
Centre for the Protection of National Infrastructure (CPNI)
Further details about CPNI, including information about our products
found at www.cpni.gov.uk
Please note that CSIRTUK RSS Feeds are available from:
Kaspersky Web Scanner ActiveX Format String Vulnerability
Date: 11 October 2007 11:28
Title: 3426 - Kaspersky Web Scanner ActiveX Format String Vulnerability
Abstract: Remote exploitation of a format string vulnerability in
Kaspersky Lab's Online Scanner virus scanner service could allow an
attacker to execute arbitrary code within the security context of the
Applications affected:Web Scanner
Advisory type: Information
Availability of fix: Available
Type of fix: Patch
Source: iDefense, Inc.
Reliability of source: Known
Source URL: http://labs.idefense.com/intelligence/vulnerabilities/
Kaspersky Web Scanner ActiveX Format String Vulnerability
iDefense Security Advisory 10.10.07
Oct 10, 2007
Kaspersky Lab Online Virus Scanner is a free online virus scanner
service, enabling a user to scan their system for malicious code via
their Web browser. This online service can be accessed at following URL.
Remote exploitation of a format string vulnerability in Kaspersky Lab's
Online Scanner virus scanner service could allow an attacker to execute
arbitrary code within the security context of the targeted user.
This vulnerability specifically exists in the Kaspersky online virus
scanner ActiveX control. The ActiveX control in question has the
This ActiveX control passes attacker supplied data as the format string
parameter of various string formatting functions. This is presumably
done to enable displaying localized messages from within the HTML page.
By rendering a specially crafted web page using this ActiveX control, a
heap based buffer overflow could occur.
Exploitation of this vulnerability would allow a remote attacker to
execute arbitrary code within the context of the targeted user. To
exploit this vulnerability, an attacker would need to persuade the
victim into viewing a malicious website.
This ActiveX control is installed during the use of the Kaspersky Online
Virus Scanner. Once the vulnerable ActiveX control is installed, it will
remain installed until they explicitly remove it. If the user doesn't
have Kaspersky Online Scanner Control installed, the exploit page could
prompt the user to install this ActiveX.
Though this is a format string vulnerability, the traditional "%n"
technique will not work. This is due to this ActiveX being compiled with
Microsoft Visual Studio 2005, in which the "%n" format specifier is
disabled by default. However, the attacker could still exploit the
vulnerability using other methods.
iDefense has confirmed the existence of this vulnerability within
version 188.8.131.52 of Kaspersky Lab's kavwebscan.dll. Previous versions
are suspected to be vulnerable.
Setting the kill-bit for this control will prevent it from being loaded
within Internet Explorer. However, doing so will also prevent legitimate
use of the control.
VI. VENDOR RESPONSE
Kaspersky Lab has addressed this vulnerability by publishing a new
version of the vulnerable ActiveX control. For more information, consult
Kaspersky's press release at the following URL.
VII. CVE INFORMATION
The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CVE-2007-3675 to this issue. This is a candidate for inclusion in
the CVE list (http://cve.mitre.org/), which standardizes names for
VIII. DISCLOSURE TIMELINE
06/20/2007 Initial vendor notification
06/21/2007 Initial vendor response
10/10/2007 Coordinated public disclosure
This vulnerability was reported to iDefense by Stephen Fewer of Harmony
Get paid for vulnerability research
Free tools, research and upcoming events http://labs.idefense.com/
X. LEGAL NOTICES
Copyright (c) 2007 iDefense, Inc.
Permission is granted for the redistribution of this alert
electronically. It may not be edited in any way without the express
written consent of iDefense. If you wish to reprint the whole or any
part of this alert in any other medium other than electronically, please
e-mail customerservice@xxxxxxxxxxxx for permission.
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,
CPNI values your feedback.
1. Which of the following most reflects the value of the advisory to
(Place an 'X' next to your choice)
Very useful:__ Useful:__ Not useful:__
2. If you did not find it useful, why not?
3. Any other comments? How could we improve our advisories?
Thank you for your contribution.
CSIRTUK wishes to acknowledge the contributions of iDefense, Inc. for
the information contained in this advisory.
This advisory contains information released by the original author. Some
information may have changed since it was released. If the issue affects
it may be prudent to retrieve the advisory from the site of the original
source to ensure that you receive the most current information
Reference to any specific commercial product, process, or service by
name, trademark manufacturer, or otherwise, does not constitute or imply
endorsement, recommendation, or favouring by CPNI. The views and
authors expressed within this notice shall not be used for advertising
product endorsement purposes.
CPNI shall not accept responsibility for any errors or omissions
within this advisory. In particular, they shall not be liable for any
damage whatsoever, arising from or in connection with the usage of
contained within this advisory.
CSIRTUK is a member of the Forum of Incident Response and Security Teams
and has contacts with other international Incident Response Teams (IRTs)
order to foster cooperation and coordination in incident prevention, to
rapid reaction to incidents, and to promote information sharing amongst
members and the community at large.
<End of CPNI Advisory>
The original of this email was scanned for viruses by the Government Secure Intranet Anti-Virus service supplied by Cable&Wireless in partnership with MessageLabs. (CCTM Certificate Number 2006/04/0007.) On leaving the GSi this email was certified virus free.
Communications via the GSi may be automatically logged, monitored and/or recorded for legal purposes.