CVE-2022-4203

Technical Description

A read buffer overrun can be triggered in X.509 certificate verification,

specifically in name constraint checking. Note that this occurs

after certificate chain signature verification and requires either a

CA to have signed the malicious certificate or for the application to

continue certificate verification despite failure to construct a path

to a trusted issuer.

The read buffer overrun might result in a crash which could lead to

a denial of service attack. In theory it could also result in the disclosure

of private memory contents (such as private keys, or sensitive plaintext)

although we are not aware of any working exploit leading to memory

contents disclosure as of the time of release of this advisory.

In a TLS client, this can be triggered by connecting to a malicious

server. In a TLS server, this can be triggered if the server requests

client authentication and a malicious client connects.

Remediation

Check the references section for vendor advisories and patches from openssl. Update openssl to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

Affected Products

References