Remote code execution in GNU Emacs

1) Exposed dangerous method or function

EUVDB-ID: #VU101890

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 - Exposed Dangerous Method or Function

Exploit availability: No

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

CPE2.3

• cpe:2.3:a:gnu:emacs:18.59:*:*:*:*:*:*:*
• cpe:2.3:a:gnu:emacs:19.34:*:*:*:*:*:*:*
• cpe:2.3:a:gnu:emacs:20.0:*:*:*:*:*:*:*

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/

Q & A

Can this vulnerability be exploited remotely?

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

How the attacker can exploit this vulnerability?

The attacker would have to trick the victim to visit a specially crafted website or open a file.

Is there known malware, which exploits this vulnerability?

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