Vulnerabilities / Threats

12/6/2017
11:30 AM
Connect Directly
Google+
Twitter
RSS
E-Mail
50%
50%

How the Major Intel ME Firmware Flaw Lets Attackers Get 'God Mode' on a Machine

Researchers at Black Hat Europe today revealed how a buffer overflow they discovered in the chip's firmware can be abused to take control of a machine - even when it's turned 'off.'

A recently discovered and now patched vulnerability in Intel microprocessors could be used by an attacker to burrow deep inside a machine and control processes and access data - even when a laptop, workstation, or server is powered down.

Researchers who discovered the flaw went public today at Black Hat Europe in London with details of their finding, a stack buffer overflow bug in the Intel Management Engine (ME) 11 system that's found in most Intel chips shipped since 2015. ME, which contains its own operating system, is a system efficiency feature that runs during startup and while the computer is on or asleep, and handles much of the communications between the processor and external devices.

An attacker would need physical, local access to a victim's machine to pull off the hack, which would give him or her so-called "god mode" control over the system, according to Positive Technologies security researchers Mark Ermolov and Maxim Goryachy, who found the flaw.

And although Intel issued a security advisory and update for the vulnerability on November 20, Ermolov and Goryachy argue that the fix doesn't prevent an attacker from using other vulnerabilities for the attack that Intel also patched in the recent ME update, including buffer overflows in the ME kernel (CVE-2017-5705), the Intel Server Platform Services Firmware kernel (CVE-2017-5706), and the Intel Trusted Execution Engine Firmware kernel (CVE-2017-5707).

All the attacker would have to do is convert the machine to a vulnerable version of ME and exploit one of the older vulns in it, they say. Those flaws "have been patched by Intel through its latest firmware release, but if an attacker has write access to the Management Engine region, they can downgrade to an older, vulnerable version of Management Engine and exploit a vulnerability that way," Goryachy told Dark Reading.

"Unfortunately, it's not possible to completely defend against this [buffer overflow] flaw" in the Intel ME, he says.

Intel OEMs can mitigate such attacks by turning off the manufacturer mode of the chip, he says. That way, they "make sure that a local vector attack … is not possible," notes Goryachy.

How the Attack Works

An attacker would need access to the "write" feature in ME, which is part of the SPI-flash chip that contains the firmware for ME and the BIOS, according to the researchers. He or she would then rewrite the flash and run a buffer overflow exploit, which would give him or her access to the ME.

"An attacker will have almost full control at the target machine, with access to memory, USB devices, and the network," Goryachy  says. "With this, an attacker could decrypt an encrypted hard disk of someone using Microsoft Bitlocker, or access content protected by DRM [Digital Rights Management], or intercept all activity on the PC, such as viewing what's on the screen, intercepting what's typed on the keyboard, and accessing data stored on disks."

It's up to Intel's OEMs to issue firmware updates, and Intel in its security advisory last month urged customers to check with their system OEMs for the updates. Enterprises also can use the open-source CHIPSEC utility to check for BIOS configuration errors, Goryachy says, and update to the latest version of the BIOS.

The Intel processors affected by the flaw are: 6th, 7th & 8th Generation Intel Core; Xeon E3-1200 v5 & v6 Product Family; Xeon Scalable Family; Xeon W Family; Atom C3000 Family; Apollo Lake Intel Atom E3900 series; Apollo Lake Intel Pentium; and CeleronG, N and J series.

This is the second major firmware vulnerability issue for Intel this year. In early May, the company disclosed a critical privilege-escalation bug in its Active Management Technology (AMT) firmware used in many Intel chips that affected AMT firmware versions dating back to 2010.

"Over the past 12 years, only two vulnerabilities allowing the execution of arbitrary code on Management Engine have been found," Goryachy says. "The AMT vulnerability only allows an attacker to bypass authentication. The vulnerability Positive Technologies discovered enables an attacker to insert invisible backdoors on a target machine."

Related Content:

Kelly Jackson Higgins is Executive Editor at DarkReading.com. She is an award-winning veteran technology and business journalist with more than two decades of experience in reporting and editing for various publications, including Network Computing, Secure Enterprise ... View Full Bio

Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
Election Websites, Back-End Systems Most at Risk of Cyberattack in Midterms
Kelly Jackson Higgins, Executive Editor at Dark Reading,  8/14/2018
Intel Reveals New Spectre-Like Vulnerability
Curtis Franklin Jr., Senior Editor at Dark Reading,  8/15/2018
Australian Teen Hacked Apple Network
Dark Reading Staff 8/17/2018
Register for Dark Reading Newsletters
White Papers
Video
Cartoon
Current Issue
Flash Poll
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2011-2765
PUBLISHED: 2018-08-20
pyro before 3.15 unsafely handles pid files in temporary directory locations and opening the pid file as root. An attacker can use this flaw to overwrite arbitrary files via symlinks.
CVE-2018-15594
PUBLISHED: 2018-08-20
arch/x86/kernel/paravirt.c in the Linux kernel before 4.18.1 mishandles certain indirect calls, which makes it easier for attackers to conduct Spectre-v2 attacks against paravirtual guests.
CVE-2018-15572
PUBLISHED: 2018-08-20
The spectre_v2_select_mitigation function in arch/x86/kernel/cpu/bugs.c in the Linux kernel before 4.18.1 does not always fill RSB upon a context switch, which makes it easier for attackers to conduct userspace-userspace spectreRSB attacks.
CVE-2018-15573
PUBLISHED: 2018-08-20
** DISPUTED ** An issue was discovered in Reprise License Manager (RLM) through 12.2BL2. Attackers can use the web interface to read and write data to any file on disk (as long as rlm.exe has access to it) via /goform/edit_lf_process with file content in the lfdata parameter and a pathname in the lf...
CVE-2018-15574
PUBLISHED: 2018-08-20
** DISPUTED ** An issue was discovered in the license editor in Reprise License Manager (RLM) through 12.2BL2. It is a cross-site scripting vulnerability in the /goform/edit_lf_get_data lf parameter via GET or POST. NOTE: the vendor has stated "We do not consider this a vulnerability."