CVEvulnerability

CVE-2020-36477

5.9 MEDIUM Published 2021-08-23 Modified 2026-06-17 Official page ↗
Status
Modified
Published
2021-08-23
Last modified
2026-06-17
Assigner
[email protected]
CVSS 3.1 ([email protected])
5.9 MEDIUM — CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
CVSS 2.0 ([email protected])
4.3 MEDIUM — AV:N/AC:M/Au:N/C:N/I:P/A:N
Weaknesses
CWE-295

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).

Affected configurations

• arm mbed tls (< 2.24.0)

Related

Weakness · CWE (1)

  • CWE-295 Improper Certificate Validation weakness

References