{"id":"ALPINE-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.","modified":"2026-08-27T22:18:01.633330772Z","published":"2022-03-23T20:15:09.833Z","upstream":["CVE-2021-3618"],"references":[{"type":"ADVISORY","url":"https://security.alpinelinux.org/vuln/CVE-2021-3618"}],"affected":[{"package":{"name":"nginx","ecosystem":"Alpine:v3.14","purl":"pkg:apk/alpine/nginx?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.20.1-r1"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-3618.json"}},{"package":{"name":"nginx","ecosystem":"Alpine:v3.15","purl":"pkg:apk/alpine/nginx?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.20.1-r1"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-3618.json"}},{"package":{"name":"nginx","ecosystem":"Alpine:v3.16","purl":"pkg:apk/alpine/nginx?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.20.1-r1"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-3618.json"}},{"package":{"name":"nginx","ecosystem":"Alpine:v3.17","purl":"pkg:apk/alpine/nginx?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.20.1-r1"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-3618.json"}},{"package":{"name":"nginx","ecosystem":"Alpine:v3.18","purl":"pkg:apk/alpine/nginx?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.20.1-r1"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-3618.json"}},{"package":{"name":"nginx","ecosystem":"Alpine:v3.19","purl":"pkg:apk/alpine/nginx?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.20.1-r1"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-3618.json"}},{"package":{"name":"nginx","ecosystem":"Alpine:v3.20","purl":"pkg:apk/alpine/nginx?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.20.1-r1"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-3618.json"}},{"package":{"name":"nginx","ecosystem":"Alpine:v3.21","purl":"pkg:apk/alpine/nginx?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.20.1-r1"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-3618.json"}},{"package":{"name":"nginx","ecosystem":"Alpine:v3.22","purl":"pkg:apk/alpine/nginx?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.20.1-r1"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-3618.json"}},{"package":{"name":"nginx","ecosystem":"Alpine:v3.23","purl":"pkg:apk/alpine/nginx?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.20.1-r1"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-3618.json"}},{"package":{"name":"nginx","ecosystem":"Alpine:v3.24","purl":"pkg:apk/alpine/nginx?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.20.1-r1"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-3618.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:H/I:H/A:N"}]}