#VU101890 Exposed dangerous method or function in Emacs - CVE-2024-53920

Vulnerability identifier: #VU101890

Vulnerability risk: High

CVSSv4.0: 5.7 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2024-53920

CWE-ID: CWE-749

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Emacs
Client/Desktop applications / Office applications

Vendor: GNU

Description

The vulnerability allows a remote attacker to compromise the affected system.

The vulnerability exists due to improper input validation in elisp-mode.el. A remote attacker can trick the victim into invoking elisp-completion-at-point (for code completion) on untrusted Emacs Lisp source code, trigger unsafe Lisp macro expansion and execute arbitrary code on the system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Emacs: 18.59 - 30.0.92

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External links
https://eshelyaron.com/posts/2024-11-27-emacs-aritrary-code-execution-and-how-to-avoid-it.html
https://git.savannah.gnu.org/cgit/emacs.git/tag/?h=emacs-30.0.92
https://git.savannah.gnu.org/cgit/emacs.git/tree/ChangeLog.4
https://news.ycombinator.com/item?id=42256409
https://yhetil.org/emacs/CAFXAjY5f4YfHAtZur1RAqH34UbYU56_t6t2Er0YEh1Sb7-W=hg%40mail.gmail.com/

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.