Vulnerability Note VU#912156

Dell BIOS in some Latitude laptops and Precision Mobile Workstations vulnerable to buffer overflow

Original Release date: 15 Aug 2013 | Last revised: 22 Aug 2013

Overview

Dell BIOS in some older Latitude laptops and Precision Mobile Workstations are vulnerable to buffer overflows (CWE-119), which can bypass the signed BIOS enforcement standard.

Description

CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer

Dell BIOS in some older Latitude laptops and Precision Mobile Workstations is vulnerable to buffer overflows in the rbu_packet.pktNum and rbu_packet.pktSize values. These values can be set by an attacker while performing an illegitimate BIOS update. The BIOS reads these values when reconstructing the BIOS image, before any signature check occurs.

More information is available from the BIOS Security presentation at Black Hat USA 2013.

Impact

By convincing a user with root or administrative privileges to execute a malicious BIOS update, an attacker can bypass the signed BIOS enforcement to install an arbitrary BIOS image that could contain a rootkit or malicious code that persists across operating system re-installations and official BIOS updates.

Solution

Apply an Update

Dell has released updated BIOS versions for the affected Latitude and Precision systems that can be downloaded from their support site. Dell has provided the following list of fixed BIOS versions:

Dell System                     Released        Rev
===================================================
Latitude D530                   8/22/2013       A12
Latitude D531                   7/16/2013       A12
Latitude D630                   7/16/2013       A19
Latitude D631                   7/26/2013       A12
Latitude D830                   7/16/2013       A17
Precision M2300                 7/16/2013       A11
Precision M4300                 7/16/2013       A17
Precision M6300                 7/16/2013       A15
Latitude E5400                  7/16/2013       A19
Latitude E5500                  7/16/2013       A19
Latitude E4200                  7/16/2013       A24
Latitude E4300                  7/16/2013       A26
Latitude E6400                  7/16/2013       A34
Latitude E6400 ATG              7/16/2013       A34
Latitude E6400 / ATG / XFR      7/16/2013       A34
Latitude XT2                    7/18/2013       A15
Latitude E6500                  7/16/2013       A29
Latitude Z600                   7/16/2013       A11
Precision M2400                 7/16/2013       A28
Precision M4400                 7/16/2013       A29
Precision M6400                 7/16/2013       A13
Precision M6500                 7/18/2013       A10

Vendor Information (Learn More)

VendorStatusDate NotifiedDate Updated
Dell Computer Corporation, Inc.Affected11 Jul 201322 Aug 2013
If you are a vendor and your product is affected, let us know.

CVSS Metrics (Learn More)

Group Score Vector
Base 6.2 AV:L/AC:H/Au:N/C:C/I:C/A:C
Temporal 4.9 E:POC/RL:OF/RC:C
Environmental 3.7 CDP:ND/TD:M/CR:ND/IR:ND/AR:ND

References

Credit

Thanks to Corey Kallenberg, John Butterworth, and Xeno Kovah of the MITRE Corporation for reporting this vulnerability. Thanks also to Rick Martinez from Dell.

This document was written by Adam Rauf.

Other Information

  • CVE IDs: CVE-2013-3582
  • Date Public: 15 Aug 2013
  • Date First Published: 15 Aug 2013
  • Date Last Updated: 22 Aug 2013
  • Document Revision: 54

Feedback

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