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Unauthorized modification of UEFI variables in UEFI systems

Vulnerability Note VU#758382

Original Release Date: 2014-06-09 | Last Revised: 2015-02-03

Overview

Certain firmware implementations may not correctly protect and validate information contained in certain UEFI variables. Exploitation of such vulnerabilities could potentially lead to bypass of security features and/or denial of service for the platform.

Description

As discussed in recent conference publications (CanSecWest 2014, Syscan 2014, and Hack-in-the-Box 2014) certain UEFI implementations do not correctly protect and validate information contained in the 'Setup' UEFI variable. On some systems, this variable can be overwritten using operating system APIs. Exploitation of this vulnerability could potentially lead to bypass of security features, such as secure boot, and/or denial of service for the platform. Please refer to the conference publications for further details.

Impact

A local attacker that obtains administrator access to the operating system may be able to modify UEFI variables. Exploitation of such vulnerabilities could potentially lead to bypass of security features and/or denial of service for the platform.

Solution

Contact your BIOS or system vendor to determine if your system is affected. Additionally, MITRE has released the open source Copernicus tool that can help determine if a particular BIOS image is affected.

Vendor Information

758382
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American Megatrends Incorporated (AMI)

Updated:  July 03, 2014

Status

  Affected

Vendor Statement

"AMI has addressed the issue on a generic basis and is working with OEMs to implement fixes for projects in the field and production. End users should contact their board manufacturer for information on when a specific updated BIOS will be available."

Vendor Information

We are not aware of further vendor information regarding this vulnerability.

Addendum

There are no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Dell Computer Corporation, Inc.

Notified:  August 30, 2013 Updated:  June 09, 2014

Status

  Affected

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

We are not aware of further vendor information regarding this vulnerability.

Addendum

There are no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Insyde Software Corporation

Updated:  February 03, 2015

Status

  Affected

Vendor Statement

"All Insyde Secure Boot variables have always been protected from RUNTIME modifications.

Insyde has reviewed the Insyde BIOS code and did find some vulnerabilities to some of the items in this report. Insyde suggested to OEM & ODM customers that they review all of their variables and protect any sensitive variables. By late 2014 Insyde had added a mechanism to assist in protecting variables. In addition, OEM & ODM customers were advised to remove RUNTIME access from as many variables as possible to meet their market requirements.

By late 2014 Insyde had implemented protection of the Boot Mode.

All of these updates were available in Tags 03.74.32 and 05.04.32 which was the 2014 work week 32 release. The internal tracking number was IB02960647.

OEM and ODM customers are advised to contact their Insyde support representative for documentation and assistance.

End users are advised to contact the manufacturer of their equipment."

Vendor Information

We are not aware of further vendor information regarding this vulnerability.

Addendum

There are no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Intel Corporation

Updated:  June 09, 2014

Status

  Affected

Vendor Statement

Intel has released firmware updates for affected Intel systems.

Vendor Information

We are not aware of further vendor information regarding this vulnerability.

Addendum

There are no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Lenovo

Updated:  October 03, 2014

Status

  Affected

Vendor Statement

Please refer to Lenovo's security advisory for information.

Vendor Information

We are not aware of further vendor information regarding this vulnerability.

Vendor References

http://support.lenovo.com/us/en/product_security/modify_uefi_variable

Addendum

There are no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

ASUSTeK Computer Inc.

Updated:  June 09, 2014

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

We are not aware of further vendor information regarding this vulnerability.

Addendum

There are no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Hewlett-Packard Company

Updated:  June 09, 2014

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

We are not aware of further vendor information regarding this vulnerability.

Addendum

There are no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Phoenix Technologies Ltd.

Updated:  June 09, 2014

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

We are not aware of further vendor information regarding this vulnerability.

Addendum

There are no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Sony Corporation

Updated:  June 10, 2014

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

We are not aware of further vendor information regarding this vulnerability.

Addendum

There are no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Toshiba

Updated:  June 10, 2014

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

We are not aware of further vendor information regarding this vulnerability.

Addendum

There are no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.


CVSS Metrics

Group Score Vector
Base 6.0 AV:L/AC:H/Au:S/C:C/I:C/A:C
Temporal 4.7 E:POC/RL:OF/RC:C
Environmental 3.5 CDP:ND/TD:M/CR:ND/IR:H/AR:ND

References

Credit

Thanks to Corey Kallenberg, Xeno Kovah, John Butterworth, and Sam Cornwell of the MITRE Corporation for reporting this vulnerability. Thanks also goes to the Advanced Threat Research and Security Center of Excellence from Intel.

This document was written by Todd Lewellen.

Other Information

CVE IDs: CVE-2014-2961
Date Public: 2014-05-27
Date First Published: 2014-06-09
Date Last Updated: 2015-02-03 13:56 UTC
Document Revision: 32

Sponsored by the Department of Homeland Security Office of Cybersecurity and Communications.