#VU51732 Security features bypass in OpenSSL

Published: 2021-03-25

Vulnerability identifier: #VU51732

Vulnerability risk: Medium

CVSSv3.1: 5.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-3450


Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Server applications / Encryption software

Vendor: OpenSSL Software Foundation


The vulnerability allows a remote attacker to bypass implemented security restrictions.

The vulnerability exists due to an error in implementation of the X509_V_FLAG_X509_STRICT flag allows an attacker to overwrite a valid CA certificate using any non-CA certificate in the chain. As a result, a remote attacker can perform MitM attack.

Install updates from vendor's website.

Vulnerable software versions

OpenSSL: 1.1.1h - 1.1.1j

External links

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.

Latest bulletins with this vulnerability