The malicious changes were submitted by JiaT75, one of the two main xz Utils developers with years of contributions to the project.
“Given the activity over several weeks, the committer is either directly involved or there was some quite severe compromise of their system,” an official with distributor OpenWall wrote in an advisory. “Unfortunately the latter looks like the less likely explanation, given they communicated on various lists about the ‘fixes’” provided in recent updates. Those updates and fixes can be found here, here, here, and here.
On Thursday, someone using the developer’s name took to a developer site for Ubuntu to ask that the backdoored version 5.6.1 be incorporated into production versions because it fixed bugs that caused a tool known as Valgrind to malfunction.
“This could break build scripts and test pipelines that expect specific output from Valgrind in order to pass,” the person warned, from an account that was created the same day.
One of maintainers for Fedora said Friday that the same developer approached them in recent weeks to ask that Fedora 40, a beta release, incorporate one of the backdoored utility versions.
“We even worked with him to fix the valgrind issue (which it turns out now was caused by the backdoor he had added),” the Ubuntu maintainer said.
He has been part of the xz project for two years, adding all sorts of binary test files, and with this level of sophistication, we would be suspicious of even older versions of xz until proven otherwise.
This is the best summary I could come up with:
Researchers have found a malicious backdoor in a compression tool that made its way into widely used Linux distributions, including those from Red Hat and Debian.
An update the following day included a malicious install script that injected itself into functions used by sshd, the binary file that makes SSH work.
So-called GIT code available in repositories aren’t affected, although they do contain second-stage artifacts allowing the injection during the build time.
In the event the obfuscated code introduced on February 23 is present, the artifacts in the GIT version allow the backdoor to operate.
“This could break build scripts and test pipelines that expect specific output from Valgrind in order to pass,” the person warned, from an account that was created the same day.
The malicious versions, researchers said, intentionally interfere with authentication performed by SSH, a commonly used protocol for connecting remotely to systems.
The original article contains 810 words, the summary contains 146 words. Saved 82%. I’m a bot and I’m open source!
So-called GIT code available in repositories aren’t affected
I wonder what convinced the model to treat git as an acronym
