Vulnerability Note VU#535111
McAfee VirusScan Enterprise for Windows scriptproxy COM object memory corruption vulnerability
Original Release date: 13 Dec 2016 | Last revised: 19 Dec 2016

Overview
McAfee VirusScan Enterprise for Windows scriptproxy COM object contains a memory corruption vulnerability.

Description
According to the reporter, McAfee VirusScan Enterprise for Windows version 8.7i through at least 8.8 patch 7 contains a scriptproxy COM object that is vulnerable to the following:
CWE-824: Access of Uninitialized Pointer

According to the reporter, when attempting to load the McAfee VirusScan Enterprise scriptproxy COM object DLL via CLSID in an HTML document through Internet Explorer, the DLL may crash in such a way as to cause an access violation on the instruction pointer, which may lead to denial of service.

The CERT/CC has not received a CVE ID assignment from McAfee for this issue at this time.
Intel Security, which owns McAfee, has provided the following response:

Intel Security takes any claim of this kind very seriously. We have requested and are awaiting the information we require to conduct our assessment. We look forward to receiving this information.

The CERT/CC has independently confirmed this issue in McAfee VirusScan Enterprise 8.8 patch 7 on Internet Explorer 11 for Windows 7 and reported details to McAfee in June 2016. It is unclear if other versions of Internet Explorer are also affected.

The CERT/CC will continue to work with Intel Security/McAfee to address this issue.

This issue was originally published as part of VU#245327, but was later moved to its own Vulnerability Note to prevent product confusion.

Impact
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 cause a denial of service.

Solution
The CERT/CC is currently unaware of a practical solution to this problem. However, affected users may consider the following workaround:
Disable the McAfee ActiveX control in Internet Explorer

The vulnerable McAfee ActiveX control can be disabled in Internet Explorer by setting the kill bit for the following CLSID:

{7DB2D5A0-7241-4E79-B68D-6309F01C5231}

More information about how to set the kill bit is available in Microsoft Support Document 240797.

Alternatively, the following text can be saved as a .REG file and imported to set the kill bit for this control:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\ActiveX Compatibility\{7DB2D5A0-7241-4E79-B68D-6309F01C5231}]
"Compatibility Flags"=dword:00000400
[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Internet Explorer\ActiveX Compatibility\{7DB2D5A0-7241-4E79-B68D-6309F01C5231}]
"Compatibility Flags"=dword:00000400

Vendor Information (Learn More)

VendorStatusDate NotifiedDate UpdatedMcAfeeAffected08 Jun 201619 Dec 2016If you are a vendor and your product is affected, let
us know.

CVSS Metrics (Learn More)

Group
Score
Vector

Base
7.6
AV:N/AC:H/Au:N/C:C/I:C/A:C

Temporal
6.1
E:U/RL:U/RC:UR

Environmental
4.6
CDP:ND/TD:M/CR:ND/IR:ND/AR:ND

References

https://cwe.mitre.org/data/definitions/824.html

Credit

Thanks to Shelby Kaba for reporting this issue to us.
This document was written by Garret Wassermann.

Other Information

CVE IDs:
Unknown

Date Public:
12 Dec 2016

Date First Published:
13 Dec 2016

Date Last Updated:
19 Dec 2016

Document Revision:
46

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