The Sky Software FileView ActiveX control contains a buffer overflow vulnerability, which may allow a remote, unauthenticated attacker to execute arbitrary code on a vulnerable system.
The Sky Software FileView object is an ActiveX control that is provided with several applications, such as WinZip. This ActiveX control contains a buffer overflow vulnerability in the handling of the
filepattern property. Exploit code for this vulnerability is publicly available.
By convincing a user to view a specially crafted HTML document (e.g., a web page or an HTML email message or attachment), an attacker may be able to execute arbitrary code with the privileges of the user. The attacker could also cause Internet Explorer (or the program using the WebBrowser control) to crash.
Apply an update
WinZip 10 users should update to Winzip 10 build 7245. This update provides a version of the FileView control that is not marked "safe for scripting" or "safe for initialization," which means that a web page cannot trigger the buffer overflow. Versions of WinZip prior to 10 do not appear to contain the vulnerable ActiveX control.
Sky Software FileView ActiveX control users should update to version 8.0 of the control. This version appears to fix the buffer overflow vulnerability.
Disabling ActiveX controls in the Internet Zone (or any zone used by an attacker) appears to prevent exploitation of this and other ActiveX vulnerabilities. Instructions for disabling ActiveX in the Internet Zone can be found in the "Securing Your Web Browser" document.
Disable the FileView object in Internet Explorer
The Sky Software FileView ActiveX controls can be disabled in Internet Explorer by setting the kill bit for the following CLSIDs. Note that this list is not a complete list of the vulnerable controls. Other versions of the FileView ActiveX control may use different CLSIDs.
More information about how to set the kill bit is available in Microsoft Support Document 240797.
Vendor| Status| Date Notified| Date Updated
Sky Software| | 24 Oct 2006| 15 Nov 2006
WinZip Computing, Inc.| | 21 Aug 2006| 15 Nov 2006
If you are a vendor and your product is affected, let us know.
Group | Score | Vector
Base | N/A | N/A
Temporal | N/A | N/A
Environmental | N/A | N/A
Thanks to Dan Plakosh and Will Dormann of CERT/CC for reporting this vulnerability. Before this vulnerability was able to reach a coordinated disclosure date, this vulnerability was publicly disclosed by Micheal Turner.
This document was written by Will Dormann.