#VU67813 Improper Certificate Validation in strongSwan - CVE-2022-40617

Vulnerability identifier: #VU67813

Vulnerability risk: Medium

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

CVE-ID: CVE-2022-40617

CWE-ID: CWE-295

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
strongSwan
Server applications / Encryption software

Vendor: strongswan.org

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to an error within the revocation plugin, which uses potentially untrusted OCSP URIs and CRL distribution points (CDP) in certificates. A remote attacker can initiate the IKE_SAs and send crafted certificates that contain URIs pointing to servers under their control. As a result, a remote attacker can perform a denial of service (DoS) attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

strongSwan: 5.0.0 - 5.9.7

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External links
https://strongswan.org/blog/2022/10/03/strongswan-vulnerability-(cve-2022-40617).html

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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.