Ubuntu update for openssh

1) Untrusted search path

EUVDB-ID: #VU78454

Risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Green]

CVE-ID: CVE-2023-38408

CWE-ID: CWE-426 - Untrusted Search Path

Exploit availability: Yes

Description

The vulnerability allows a remote attacker to compromise the affected system.

The vulnerability exists due to usage of an insecure search path within the PKCS#11 feature in ssh-agent. A remote attacker can trick the victim into connecting to a malicious SSH server and execute arbitrary code on the system, if an agent is forwarded to an attacker-controlled system.

Note, this vulnerability exists due to incomplete fix for #VU2015 (CVE-2016-10009).

Mitigation

Update the affected package openssh to the latest version.

Vulnerable software versions

Ubuntu: 20.04 - 23.04

openssh-client (Ubuntu package): before 1:8.2p1-4ubuntu0.8

CPE2.3

• cpe:2.3:o:canonical:ubuntu:20.04:*:*:*:*:*:*:*
• cpe:2.3:o:canonical:ubuntu:22.04:*:*:*:*:*:*:*
• cpe:2.3:o:canonical:ubuntu:23.04:*:*:*:*:*:*:*
• cpe:2.3:o:canonical:openssh-client_ubuntu_package:*:*:*:*:*:ubuntu:*:*

External links

https://ubuntu.com/security/notices/USN-6242-1

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. However, proof of concept for this vulnerability is available.