How to Bypass Authentication on a Linux System
Major bug affects Debian/Ubuntu distributions.
Researchers have discovered a flaw in the Cryptsetup utility that allows an attacker to bypass the authentication process on some Linux-based systems just by pressing and holding the Enter key for 70 seconds.
Debian/Ubuntu-based systems with encrypted system partitions are affected by this vulnerability. Researchers warn that other distributions using Dracut instead of initramfs are also vulnerable.
Hector Marco and Ismael Ripoll from the Cybersecurity Group explained in their security advisory that the vulnerability allows you to obtain a root initramfs shell on the affected system. “The vulnerability is very reliable because it doesn't depend on specific systems or configurations. Attackers can copy, modify, or destroy the hard disk as well as setup the network to exfiltrate data. This vulnerability is especially serious in environments like libraries, ATMs, airport machines, labs, etc, where the whole boot process is protected (password in BIOS and GRUB) and you only have a keyboard and/or a mouse,” Marco and Ripol wrote.
The worst thing about this vulnerability is that you don’t need physical access to the machine; it is possible to exploit the vulnerability remotely in cloud environments.
Last year, the same researchers discovered a bug in GRUB 2 that allowed an attacker to bypass all securities on a locked-down Linux machine by hitting the Enter key 28 times when asked for a user name.
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Support Our Work
Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.
News
-
Linux Servers Targeted by Akira Ransomware
A group of bad actors who have already extorted $42 million have their sights set on the Linux platform.
-
TUXEDO Computers Unveils Linux Laptop Featuring AMD Ryzen CPU
This latest release is the first laptop to include the new CPU from Ryzen and Linux preinstalled.
-
XZ Gets the All-Clear
The back door xz vulnerability has been officially reverted for Fedora 40 and versions 38 and 39 were never affected.
-
Canonical Collaborates with Qualcomm on New Venture
This new joint effort is geared toward bringing Ubuntu and Ubuntu Core to Qualcomm-powered devices.
-
Kodi 21.0 Open-Source Entertainment Hub Released
After a year of development, the award-winning Kodi cross-platform, media center software is now available with many new additions and improvements.
-
Linux Usage Increases in Two Key Areas
If market share is your thing, you'll be happy to know that Linux is on the rise in two areas that, if they keep climbing, could have serious meaning for Linux's future.
-
Vulnerability Discovered in xz Libraries
An urgent alert for Fedora 40 has been posted and users should pay attention.
-
Canonical Bumps LTS Support to 12 years
If you're worried that your Ubuntu LTS release won't be supported long enough to last, Canonical has a surprise for you in the form of 12 years of security coverage.
-
Fedora 40 Beta Released Soon
With the official release of Fedora 40 coming in April, it's almost time to download the beta and see what's new.
-
New Pentesting Distribution to Compete with Kali Linux
SnoopGod is now available for your testing needs