CVE-2020-36477

 

Published at: - 23-08-2021 04:15

Last modified: - 13-01-2023 08:59

Total changes: - 5

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).

Common Vulnerability Scoring System (CVSS)

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N

 

Verification logic

 

Reference

• https://github.com/ARMmbed/mbedtls/releases/tag/v2.24.0
• https://github.com/ARMmbed/mbedtls/issues/3498
• GLSA-202301-08-Third Party Advisory

 

Keywords

NVD

 

CVE-2020-36477

 

CVE

 

Common vulnerabilities & exposures

 

CVSS

 

Common vulnerability scoring system

 

Security

 

Vulnerabilities

 

Exposures