Privilege escalation in Sudo

1) Input validation error

EUVDB-ID: #VU71332

Risk: Low

CVSSv3.1: 7.2 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C]

CVE-ID: CVE-2023-22809

CWE-ID: CWE-20 - Improper input validation

Exploit availability: Yes

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists within the sudoedit (aka -e) feature due to insufficient validation of user-supplied input passed in the user-provided environment variables (SUDO_EDITOR, VISUAL, and EDITOR). The problem exists because a user-specified editor may contain a "--" argument that defeats a protection mechanism, e.g., an EDITOR='vim -- /path/to/extra/file' value. A local user can append arbitrary entries to the list of files to process and escalate privileges on the system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Sudo: 1.3.1 - 1.9.12p1

External links

http://www.synacktiv.com/sites/default/files/2023-01/sudo-CVE-2023-22809.pdf
http://www.sudo.ws/security/advisories/sudoedit_any/

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, a fully functional exploit for this vulnerability is available.