{"id":"CVE-2021-34433","details":"In Eclipse Californium version 2.0.0 to 2.6.4 and 3.0.0-M1 to 3.0.0-M3, the certificate based (x509 and RPK) DTLS handshakes accidentally succeeds without verifying the server side's signature on the client side, if that signature is not included in the server's ServerKeyExchange.","modified":"2026-08-27T08:40:38.710289Z","published":"2021-08-20T17:15:07.687Z","references":[{"type":"REPORT","url":"https://bugs.eclipse.org/bugs/show_bug.cgi?id=575281"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/eclipse-californium/californium","events":[{"introduced":"15a27a972d7b4dd8d28d717cedfd01e6bf860e38"},{"fixed":"896b12c5a582787bed4dc971b0b0f675009b2401"},{"introduced":"8f6f689bcc03377f682d8c3b86c705ce02225afd"},{"last_affected":"b5780bb2e17efb708e46242a204094ff1cdad034"}],"database_specific":{"cpe":["cpe:2.3:a:eclipse:californium:*:*:*:*:*:*:*:*","cpe:2.3:a:eclipse:californium:3.0.0:m1:*:*:*:*:*:*","cpe:2.3:a:eclipse:californium:3.0.0:m2:*:*:*:*:*:*","cpe:2.3:a:eclipse:californium:3.0.0:m3:*:*:*:*:*:*"],"extracted_events":[{"introduced":"2.0.0"},{"fixed":"2.6.5"},{"introduced":"3.0.0-m1"},{"last_affected":"3.0.0-m1"},{"introduced":"3.0.0-m2"},{"last_affected":"3.0.0-m2"},{"introduced":"3.0.0-m3"},{"last_affected":"3.0.0-m3"}],"source":["CPE_RANGE","CPE_STRING"]}}],"versions":["3.0.0-m1","3.0.0-m2","3.0.0-m3","3.0.0-M3","2.6.4","3.0.0-M2","2.6.3","3.0.0-M1","2.6.2","2.6.1","2.6.0","2.5.0","2.4.0","2.3.0","2.3.0-RC2","2.3.0-RC1","2.2.0","2.2.0-RC1","2.1.0","2.1.0-RC2","2.1.0-RC1","2.0.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-34433.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"}]}