#VU61608 Improper Authentication in OpenVPN for Windows - CVE-2022-0547

Vulnerability identifier: #VU61608

Vulnerability risk: Medium

CVSSv4.0: 1.7 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2022-0547

CWE-ID: CWE-287

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
OpenVPN for Windows
Client/Desktop applications / Software for system administration

Vendor: OpenVPN

Description

The vulnerability allows a remote attacker to bypass authentication process.

The vulnerability exists due to an error when processing authentication requests in external authentication plug-ins when more than one of them makes use of deferred authentication replies. A remote attacker can bypass authentication process and gain unauthorized access to the network with only partially correct credentials.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

OpenVPN for Windows: 2.1 - 2.1.28.0, 2.2 - 2.2.3, 2.3.0 - 2.3.18, 2.4.0 - 2.4.11, 2.5.0 - 2.5.5

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External links
https://community.openvpn.net/openvpn/wiki/SecurityAnnouncements
https://community.openvpn.net/openvpn/wiki/CVE-2022-0547

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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.