CVE-2020-36477
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).
Does this matter?
Lower severity and a low EPSS score (0.83%). Track it; it rarely justifies an emergency change on its own.
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 3.1
- 5.9 MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
- EPSS
- 0.83% probability · 56th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-295
- Affected
- arm/mbed tls
- Source
- cve@mitre.org
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
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.