CVE-2024-53920: Detailed Vulnerability Analysis and Overview

CVE-2024-53920 Vulnerability Summary

In elisp-mode.el in GNU Emacs through 30.0.92, a user who chooses to invoke elisp-completion-at-point (for code completion) on untrusted Emacs Lisp source code can trigger unsafe Lisp macro expansion that allows attackers to execute arbitrary code. (This unsafe expansion also occurs if a user chooses to enable on-the-fly diagnosis that byte compiles untrusted Emacs Lisp source code.)

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CVE-2024-53920: Detailed Information and External References

EPSS

0.00045

EPSS %

0.17329

References

0.00045

• 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/

CWE

CWE-94

CAPEC

0.00045

• Code Injection: An adversary exploits a weakness in input validation on the target to inject new code into that which is currently executing. This differs from code inclusion in that code inclusion involves the addition or replacement of a reference to a code file, which is subsequently loaded by the target and used as part of the code of some application.
• Leverage Executable Code in Non-Executable Files: An attack of this type exploits a system's trust in configuration and resource files. When the executable loads the resource (such as an image file or configuration file) the attacker has modified the file to either execute malicious code directly or manipulate the target process (e.g. application server) to execute based on the malicious configuration parameters. Since systems are increasingly interrelated mashing up resources from local and remote sources the possibility of this attack occurring is high.
• Manipulating User-Controlled Variables: This attack targets user controlled variables (DEBUG=1, PHP Globals, and So Forth). An adversary can override variables leveraging user-supplied, untrusted query variables directly used on the application server without any data sanitization. In extreme cases, the adversary can change variables controlling the business logic of the application. For instance, in languages like PHP, a number of poorly set default configurations may allow the user to override variables.

CVSS3 Source

134c704f-9b21-4f2e-91b3-4a467353bcc0

CVSS3 Type

Secondary

CVSS3 Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H