libcue Library Flaw Exposes GNOME Linux Systems to RCE Attacks

Rohan Timalsina

October 24, 2023 - TuxCare expert team

A memory corruption vulnerability within the open-source libcue library allows attackers to execute arbitrary code on Linux systems running the GNOME desktop environment.

The libcue library, primarily designed for parsing cue sheet files, is seamlessly integrated into the Tracker Miners file metadata indexer, which comes as a default component in the latest GNOME versions.

Cue sheets, also known as CUE files, are plaintext documents that define the layout of audio tracks on a CD, encompassing details like track duration, song titles, and artist information. These files are commonly used in conjunction with the FLAC audio format.

GNOME stands as a popular desktop environment, widely adopted across several Linux distributions, including Debian, Ubuntu, Fedora, Red Hat Enterprise, and SUSE Linux Enterprise.

Malicious actors can exploit this identified vulnerability (CVE-2023-43641) to execute harmful code by leveraging Tracker Miners, which automatically index all downloaded files to update the search index on GNOME Linux devices.

libcue Library Flaw – CVE-2023-43641

CVSS v3 Base Score: 8.8 High

The root cause of this problem is an out-of-bounds array access within the track_set_index function. This vulnerability enables malicious actors to execute code on the target machine by luring a victim into clicking a malevolent link and downloading a .cue file.

As per the description in the National Vulnerability Database (NVD), this vulnerability allows a user of the GNOME desktop environment to fall victim to exploitation simply by downloading a cue sheet from a malicious website. Tracker-miners automatically scan the file upon saving to ~/Downloads and, given its .cue filename extension, tracker-miners employ libcue for parsing the file, thus facilitating code execution.

In the interest of user security, we deliberately withheld certain technical details about the vulnerability, affording users adequate time to install the latest updates.

As GitHub security researcher Kevin Backhouse points out, seemingly innocuous libraries can wield substantial impact. The specific usage of libcue by tracker-miners has transformed this vulnerability into a one-click RCE threat.

This disclosure emerged two weeks after GitHub’s comprehensive disclosure of CVE-2023-3420, a high-severity type confusion vulnerability in the Google Chrome V8 JavaScript engine. This flaw permits remote code execution (RCE) in the renderer sandbox of the web browser upon visiting a malicious site.

Final Thoughts

A critical security flaw has come to light in the libcue library, impacting GNOME Linux systems and leaving them susceptible to remote code execution (RCE) exploits. Tracked as CVE-2023-43641 with a high CVSS score of 8.8, this flaw revolves around memory corruption within libcue, a library primarily designed for parsing cue sheet files, affecting versions 2.2.1 and earlier.

Security researcher Man Yue Mo underscores that vulnerabilities like these often serve as a launchpad for ‘one-click’ exploits, compromising the victim’s device when they visit a nefarious website. A renderer RCE in Chrome empowers attackers to compromise and execute arbitrary code within the Chrome renderer process. Stay informed and vigilant about these critical security developments.

The sources for this article include a story from TheHackerNews.

Summary