Privilege escalation in OpenPrinting cupsd

1) UNIX symbolic link following

EUVDB-ID: #VU92075

Risk: Low

CVSSv4.0: 7.1 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Clear]

CVE-ID: CVE-2024-35235

CWE-ID: CWE-61 - UNIX Symbolic Link (Symlink) Following

Exploit availability: Yes

Description

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

The vulnerability exists due to a symlink following issue. A local user can create a specially crafted symbolic link to a critical file on the system and make it world-writable.

Successful exploitation of this vulnerability may result in privilege escalation.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

cups: 2.2.7 - 2.4.8

CPE2.3

• cpe:2.3:a:OpenPrinting:cups:2.2.7:*:*:*:*:*:*:*
• cpe:2.3:a:OpenPrinting:cups:2.2.8:*:*:*:*:*:*:*
• cpe:2.3:a:OpenPrinting:cups:2.2.9:*:*:*:*:*:*:*

External links

https://github.com/OpenPrinting/cups/security/advisories/GHSA-vvwp-mv6j-hw6f
https://github.com/OpenPrinting/cups/commit/ff1f8a623e090dee8a8aadf12a6a4b25efac143d
https://git.launchpad.net/ubuntu/+source/apparmor/tree/profiles/apparmor.d/abstractions/user-tmp#n21
https://github.com/OpenPrinting/cups/blob/aba917003c8de55e5bf85010f0ecf1f1ddd1408e/cups/http-addr.c#L229-L240
https://www.openwall.com/lists/oss-security/2024/06/11/1
https://www.openwall.com/lists/oss-security/2024/06/12/4
https://www.openwall.com/lists/oss-security/2024/06/12/5
https://github.com/OpenPrinting/cups/releases/tag/v2.4.9

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, proof of concept for this vulnerability is available.