{"id":"DEBIAN-CVE-2020-36477","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).","modified":"2026-09-11T11:02:46.679512549Z","published":"2021-08-23T02:15:07.043Z","upstream":["CVE-2020-36477"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2020-36477"}],"affected":[{"package":{"name":"mbedtls","ecosystem":"Debian:12","purl":"pkg:deb/debian/mbedtls?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.28.0-0.3"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2020-36477.json"}},{"package":{"name":"mbedtls","ecosystem":"Debian:13","purl":"pkg:deb/debian/mbedtls?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.28.0-0.3"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2020-36477.json"}},{"package":{"name":"mbedtls","ecosystem":"Debian:14","purl":"pkg:deb/debian/mbedtls?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.28.0-0.3"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2020-36477.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N"}]}