{"id":"CVE-2020-36478","details":"An issue was discovered in Mbed TLS before 2.25.0 (and before 2.16.9 LTS and before 2.7.18 LTS). A NULL algorithm parameters entry looks identical to an array of REAL (size zero) and thus the certificate is considered valid. However, if the parameters do not match in any way, then the certificate should be considered invalid.","modified":"2026-03-10T23:21:12.232284Z","published":"2021-08-23T02:15:07.097Z","references":[{"type":"WEB"},{"type":"ADVISORY","url":"https://github.com/ARMmbed/mbedtls/releases/tag/v2.25.0"},{"type":"ADVISORY","url":"https://github.com/ARMmbed/mbedtls/releases/tag/v2.7.18"},{"type":"ADVISORY","url":"https://lists.debian.org/debian-lts-announce/2021/11/msg00021.html"},{"type":"ADVISORY","url":"https://lists.debian.org/debian-lts-announce/2022/12/msg00036.html"},{"type":"ADVISORY","url":"https://github.com/ARMmbed/mbedtls/releases/tag/v2.16.9"},{"type":"FIX","url":"https://cert-portal.siemens.com/productcert/pdf/ssa-756638.pdf"},{"type":"EVIDENCE","url":"https://github.com/ARMmbed/mbedtls/issues/3629"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/armmbed/mbedtls","events":[{"introduced":"0"},{"fixed":"78d9663acec4ac72af43e2db57fc73a24e856108"},{"introduced":"8be0e6db41b4a085e90cb03983f99d3a5158d450"},{"fixed":"3fac0bae4a50113989b3d015cd2d948f51a6d9ac"},{"introduced":"3f8d78411a26e833db18d9fbde0e2f0baeda87f0"},{"fixed":"1c54b5410fd48d6bcada97e30cac417c5c7eea67"},{"introduced":"0"},{"fixed":"8254ed2a9fadede8c6bf414072f78fc78d5af61c"},{"introduced":"0"},{"fixed":"8254ed2a9fadede8c6bf414072f78fc78d5af61c"}],"database_specific":{"versions":[{"introduced":"0"},{"fixed":"2.7.18"},{"introduced":"2.8.0"},{"fixed":"2.16.9"},{"introduced":"2.17.0"},{"fixed":"2.25.0"},{"introduced":"0"},{"fixed":"2.2"},{"introduced":"0"},{"fixed":"2.2"}]}},{"repo":"https://github.com/mbed-tls/mbedtls","events":[{"introduced":"0"},{"fixed":"3fac0bae4a50113989b3d015cd2d948f51a6d9ac"},{"fixed":"1c54b5410fd48d6bcada97e30cac417c5c7eea67"},{"fixed":"78d9663acec4ac72af43e2db57fc73a24e856108"}]}],"versions":["mbedtls-2.10.0","mbedtls-2.11.0","mbedtls-2.12.0","mbedtls-2.13.0","mbedtls-2.13.1","mbedtls-2.14.0","mbedtls-2.15.0","mbedtls-2.15.1","mbedtls-2.16.0","mbedtls-2.16.1","mbedtls-2.16.2","mbedtls-2.16.3","mbedtls-2.16.4","mbedtls-2.16.5","mbedtls-2.16.6","mbedtls-2.16.7","mbedtls-2.16.8","mbedtls-2.17.0","mbedtls-2.18.0","mbedtls-2.19.0","mbedtls-2.19.0d1","mbedtls-2.19.0d2","mbedtls-2.19.1","mbedtls-2.20.0","mbedtls-2.20.0d0","mbedtls-2.20.0d1","mbedtls-2.21.0","mbedtls-2.22.0","mbedtls-2.22.0d0","mbedtls-2.23.0","mbedtls-2.24.0","mbedtls-2.8.0","mbedtls-2.9.0","v2.16.7","v2.16.8","v2.23.0","v2.24.0"],"database_specific":{"unresolved_ranges":[{"events":[{"introduced":"0"},{"last_affected":"9.0"}]},{"events":[{"introduced":"0"},{"last_affected":"10.0"}]}],"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-36478.json"}}],"schema_version":"1.7.3","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"}]}