Vulnerability 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).
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Arm | Mbed Tls | < 2.24.0 |
Related Weaknesses (CWE)
References
- https://github.com/ARMmbed/mbedtls/issues/3498Third Party Advisory
- https://github.com/ARMmbed/mbedtls/releases/tag/v2.24.0Release NotesThird 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 NotesThird Party Advisory
- https://security.gentoo.org/glsa/202301-08Third Party Advisory
FAQ
What is CVE-2020-36477?
CVE-2020-36477 is a vulnerability with a CVSS score of 5.9 (MEDIUM). 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 certificat...
How severe is CVE-2020-36477?
CVE-2020-36477 has been rated MEDIUM with a CVSS base score of 5.9/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2020-36477?
Check the references section above for vendor advisories and patch information. Affected products include: Arm Mbed Tls.