{"id":"CVE-2021-3618","details":"ALPACA is an application layer protocol content confusion attack, exploiting TLS servers implementing different protocols but using compatible certificates, such as multi-domain or wildcard certificates. A MiTM attacker having access to victim's traffic at the TCP/IP layer can redirect traffic from one subdomain to another, resulting in a valid TLS session. This breaks the authentication of TLS and cross-protocol attacks may be possible where the behavior of one protocol service may compromise the other at the application layer.","aliases":["BIT-nginx-2021-3618","BIT-nginx-gateway-2021-3618"],"modified":"2026-03-14T11:01:51.629786Z","published":"2022-03-23T20:15:09.833Z","related":["MGASA-2021-0540","SUSE-RU-2022:0655-1","SUSE-SU-2022:3320-1","SUSE-SU-2022:3383-1","SUSE-SU-2022:3457-1","SUSE-SU-2022:3458-1","SUSE-SU-2022:3888-1","SUSE-SU-2022:4192-1","SUSE-SU-2022:4201-1","SUSE-SU-2022:4265-1","SUSE-SU-2022:4266-1"],"references":[{"type":"ADVISORY","url":"https://alpaca-attack.com/"},{"type":"ADVISORY","url":"https://lists.debian.org/debian-lts-announce/2022/11/msg00031.html"},{"type":"FIX","url":"https://bugzilla.redhat.com/show_bug.cgi?id=1975623"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/nginx/nginx","events":[{"introduced":"0"},{"fixed":"ffcf93a6bf0c203c136e9ee9d65b81659ca9f7b6"}],"database_specific":{"versions":[{"introduced":"0"},{"fixed":"1.21.0"}]}}],"versions":["release-0.1.0","release-0.1.1","release-0.1.10","release-0.1.11","release-0.1.12","release-0.1.13","release-0.1.14","release-0.1.15","release-0.1.16","release-0.1.17","release-0.1.18","release-0.1.19","release-0.1.2","release-0.1.20","release-0.1.21","release-0.1.22","release-0.1.23","release-0.1.24","release-0.1.25","release-0.1.26","release-0.1.27","release-0.1.28","release-0.1.29","release-0.1.3","release-0.1.30","release-0.1.31","release-0.1.32","release-0.1.33","release-0.1.34","release-0.1.35","release-0.1.36","release-0.1.37","release-0.1.38","release-0.1.39","release-0.1.4","release-0.1.40","release-0.1.41","release-0.1.42","release-0.1.43","release-0.1.44","release-0.1.45","release-0.1.5","release-0.1.6","release-0.1.7","release-0.1.8","release-0.1.9","release-0.2.0","release-0.2.1","release-0.2.2","release-0.2.3","release-0.2.4","release-0.2.5","release-0.2.6","release-0.3.0","release-0.3.1","release-0.3.10","release-0.3.11","release-0.3.12","release-0.3.13","release-0.3.14","release-0.3.15","release-0.3.16","release-0.3.17","release-0.3.18","release-0.3.19","release-0.3.2","release-0.3.20","release-0.3.21","release-0.3.22","release-0.3.23","release-0.3.24","release-0.3.25","release-0.3.26","release-0.3.27","release-0.3.28","release-0.3.29","release-0.3.3","release-0.3.30","release-0.3.31","release-0.3.32","release-0.3.33","release-0.3.34","release-0.3.35","release-0.3.36","release-0.3.37","release-0.3.38","release-0.3.39","release-0.3.4","release-0.3.40","release-0.3.41","release-0.3.42","release-0.3.43","release-0.3.44","release-0.3.45","release-0.3.46","release-0.3.47","release-0.3.48","release-0.3.49","release-0.3.5","release-0.3.50","release-0.3.51","release-0.3.52","release-0.3.53","release-0.3.54","release-0.3.55","release-0.3.56","release-0.3.57","release-0.3.58","release-0.3.59","release-0.3.6","release-0.3.60","release-0.3.61","release-0.3.7","release-0.3.8","release-0.3.9","release-0.4.0","release-0.4.1","release-0.4.10","release-0.4.11","release-0.4.12","release-0.4.13","release-0.4.14","release-0.4.2","release-0.4.3","release-0.4.4","release-0.4.5","release-0.4.6","release-0.4.7","release-0.4.8","release-0.4.9","release-0.5.0","release-0.5.1","release-0.5.10","release-0.5.11","release-0.5.12","release-0.5.13","release-0.5.14","release-0.5.15","release-0.5.16","release-0.5.17","release-0.5.18","release-0.5.19","release-0.5.2","release-0.5.20","release-0.5.21","release-0.5.22","release-0.5.23","release-0.5.24","release-0.5.25","release-0.5.3","release-0.5.4","release-0.5.5","release-0.5.6","release-0.5.7","release-0.5.8","release-0.5.9","release-0.6.0","release-0.6.1","release-0.6.10","release-0.6.11","release-0.6.12","release-0.6.13","release-0.6.14","release-0.6.15","release-0.6.16","release-0.6.17","release-0.6.18","release-0.6.19","release-0.6.2","release-0.6.20","release-0.6.21","release-0.6.22","release-0.6.23","release-0.6.24","release-0.6.25","release-0.6.26","release-0.6.27","release-0.6.28","release-0.6.29","release-0.6.3","release-0.6.30","release-0.6.31","release-0.6.4","release-0.6.5","release-0.6.6","release-0.6.7","release-0.6.8","release-0.6.9","release-0.7.0","release-0.7.1","release-0.7.10","release-0.7.11","release-0.7.12","release-0.7.13","release-0.7.14","release-0.7.15","release-0.7.16","release-0.7.17","release-0.7.18","release-0.7.19","release-0.7.2","release-0.7.20","release-0.7.21","release-0.7.22","release-0.7.23","release-0.7.24","release-0.7.25","release-0.7.26","release-0.7.27","release-0.7.28","release-0.7.29","release-0.7.3","release-0.7.30","release-0.7.31","release-0.7.32","release-0.7.33","release-0.7.34","release-0.7.35","release-0.7.36","release-0.7.37","release-0.7.38","release-0.7.39","release-0.7.4","release-0.7.40","release-0.7.41","release-0.7.42","release-0.7.43","release-0.7.44","release-0.7.45","release-0.7.46","release-0.7.47","release-0.7.48","release-0.7.49","release-0.7.5","release-0.7.50","release-0.7.51","release-0.7.52","release-0.7.53","release-0.7.54","release-0.7.55","release-0.7.56","release-0.7.57","release-0.7.58","release-0.7.59","release-0.7.6","release-0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