title: X.509 Email Address Variable Length Buffer Overflow
description: A 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 a malicious certificate or for an application to continue certificate verification despite failure to construct a path to a trusted issuer. An attacker can craft a malicious email address in a certificate to overflow an arbitrary number of bytes containing the `.' character (decimal 46) on the stack. This buffer overflow could result in a crash (causing a denial of service). 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.
problem types: Buffer overflow
affected:
{
defaultStatus: unaffected
product: OpenSSL
vendor: OpenSSL
versions:
lessThan: 3.0.7, status: affected, version: 3.0.0, versionType: semver
}
metrics:
format: other
other: [
content: {'text': 'HIGH'}
type: https://www.openssl.org/policies/secpolicy.html#high
]