An issue was discovered in Mbed TLS before 2.24.0. The verification of X.509 certificates when matching the expected common name (the cn argument of mbedtls_x509_crt_verify) with the actual certificate name is mishandled: when the subjecAltName extension is present, the expected name is compared to any name in that extension regardless of its type. This means that an attacker could impersonate a 4-byte or 16-byte domain by getting a certificate for the corresponding IPv4 or IPv6 address (this would require the attacker to control that IP address, though).
The product does not validate, or incorrectly validates, a certificate.
| Link | Tags |
|---|---|
| https://github.com/ARMmbed/mbedtls/releases/tag/v2.24.0 | third party advisory release notes |
| https://github.com/ARMmbed/mbedtls/issues/3498 | third party advisory |
| https://security.gentoo.org/glsa/202301-08 | third party advisory vendor advisory |