Researchers warn of a new attack which can be carried out in less than 30 seconds and potentially affects millions of laptops globally.
As Intel was rushing to roll out patches for Meltdown and Spectre vulnerabilities, security researchers have discovered a new critical security flaw in Intel hardware that could allow hackers to access corporate laptops remotely.
Finnish cyber security firm F-Secure reported unsafe and misleading default behaviour within Intel Active Management Technology (AMT) that could allow an attacker to bypass login processes and take complete control over a user’s device in less than 30 seconds.
AMT is a feature that comes with Intel-based chipsets to enhance the ability of IT administrators and managed service providers for better controlling their device fleets, allowing them to remotely manage and repair PCs, workstations, and servers in their organisation.
The bug allows anyone with physical access to the affected laptop to bypass the need to enter login credentials—including user, BIOS and BitLocker passwords and TPM pin codes—enabling remote administration for post-exploitation.
In general, setting a BIOS password prevents an unauthorised user from booting up the device or making changes to the boot-up process. But this is not the case here.
The password doesn’t prevent unauthorised access to the AMT BIOS extension, thus allowing attackers access to configure AMT and making remote exploitation possible.
Although researchers have discovered some severe AMT vulnerabilities in the past, the recently discovered issue is of particular concern because it is:
- easy to exploit without a single line of code,
- affects most Intel corporate laptops, and
- could enable attackers to gain remote access to the affected system for later exploitation.
“The attack is almost deceptively simple to enact, but it has incredible destructive potential,” said F-Secure senior security researcher Harry Sintonen, who discovered the issue in July last year.
“In practice, it can give a local attacker complete control over an individual’s work laptop, despite even the most extensive security measures.”
According to the researchers, the newly discovered bug has nothing to do with the Spectre and Meltdown vulnerabilities recently found in the microchips used in almost all PCs, laptops, smartphones and tablets today.
Here’s How to Exploit this AMT Issue
To exploit this issue, all an attacker with physical access to a password (login and BIOS) protected machine needs to do is reboot or power-up the targeted PC and press CTRL-P during boot-up, as demonstrated by researchers at F-Secure in the above video.
The attacker then can log into Intel Management Engine BIOS Extension (MEBx) with a default password.
Here, the default password for MEBx is “admin,” which most likely remains unchanged on most corporate laptops.
Once logged in, the attacker can then change the default password and enable remote access, and even set AMT’s user opt-in to “None.”
Now, since the attacker has backdoored the machine efficiently, he/she can access the system remotely by connecting to the same wireless or wired network as the victim.
Although exploiting the issue requires physical access, Sintonen explained that the speed and time at which it can be carried out makes it easily exploitable, adding that even one minute of a distraction of a target from its laptop is enough to do the damage.
“Attackers have identified and located a target they wish to exploit. They approach the target in a public place—an airport, a café or a hotel lobby—and engage in an ‘evil maid’ scenario,” Sintonen says.
“Essentially, one attacker distracts the mark, while the other briefly gains access to his or her laptop. The attack doesn’t require a lot of time—the whole operation can take well under a minute to complete.“
Along with CERT-Coordination Center in the United States, F-Secure has notified Intel and all relevant device manufacturers about the security issue and urged them to address it urgently.
Meanwhile, users and IT administrators in an organisation are recommended to change the default AMT password of their device to a strong one or disable AMT if this option is available, and never leave their laptop or PC unattended in a public place.