Description
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).
Metrics
CVSS 3.1 5.9/10
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:NWeakness enumeration
Affected software
| Vendor | Product | Versions |
|---|---|---|
| n/a | n/a | n/a |
References
- https://github.com/ARMmbed/mbedtls/issues/3498Third Party Advisory
- https://github.com/ARMmbed/mbedtls/releases/tag/v2.24.0Release Notes, Third Party Advisory
- https://security.gentoo.org/glsa/202301-08Third Party Advisory
- https://github.com/ARMmbed/mbedtls/issues/3498Third Party Advisory
- https://github.com/ARMmbed/mbedtls/releases/tag/v2.24.0Release Notes, Third Party Advisory
- https://security.gentoo.org/glsa/202301-08Third Party Advisory
Timeline
- Published
- Aug 23, 2021
- Last modified
- Jun 17, 2026
- NVD status
- Modified