Vulnerability identifier: #VU74002

Vulnerability risk: High

CVSSv3.1: 7.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2023-27986

CWE-ID: CWE-94

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Emacs
Client/Desktop applications / Office applications

Vendor: GNU

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to improper input validation when parsing data passed via the mailto: URI. A remote attacker can trick the victim to click on a specially crafted URL and execute arbitrary Emacs Lisp code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Emacs: 28.1 - 28.3 rc1

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External links
http://www.openwall.com/lists/oss-security/2023/03/08/2
http://git.savannah.gnu.org/cgit/emacs.git/commit/?h=emacs-29&id=3c1693d08b0a71d40a77e7b40c0ebc42dca2d2cc
http://www.openwall.com/lists/oss-security/2023/03/09/1

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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.