CVE-2020-36477

    Dashboard / Vulnerabilities / CVE-2020-36477

    CVE-2020-36477

    Published: 23 Aug 2021Last Modified: 27 Aug 2026

    Summary:

    Details: 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).

    References: https://github.com/ARMmbed/mbedtls/issues/3498, https://github.com/ARMmbed/mbedtls/releases/tag/v2.24.0, https://security.gentoo.org/glsa/202301-08

    Affected packages

    Package

    Name:

    Purl:

    Affected ranges

    Type: GIT

    Events:

    Introduced- 0
    Fixed -523f0554b6cdc7ace5d360885c3f5bbcc73ec0e8

    Affected versions

    mbedtls-2.19.1
    mbedtls-2.19.0d2
    mbedtls-2.19.0
    mbedtls-2.19.0d1

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High
    CVE-2020-36477 | CVE-DB