{"id":"DEBIAN-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":"2026-09-15T09:01:40.932247054Z","published":"2022-03-23T20:15:09.833Z","upstream":["CVE-2021-3618"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2021-3618"}],"affected":[{"package":{"name":"nginx","ecosystem":"Debian:12","purl":"pkg:deb/debian/nginx?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.20.2-2"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2021-3618.json"}},{"package":{"name":"nginx","ecosystem":"Debian:13","purl":"pkg:deb/debian/nginx?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.20.2-2"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2021-3618.json"}},{"package":{"name":"nginx","ecosystem":"Debian:14","purl":"pkg:deb/debian/nginx?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.20.2-2"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2021-3618.json"}},{"package":{"name":"sendmail","ecosystem":"Debian:12","purl":"pkg:deb/debian/sendmail?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"8.16.1-2"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2021-3618.json"}},{"package":{"name":"sendmail","ecosystem":"Debian:13","purl":"pkg:deb/debian/sendmail?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"8.16.1-2"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2021-3618.json"}},{"package":{"name":"sendmail","ecosystem":"Debian:14","purl":"pkg:deb/debian/sendmail?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"8.16.1-2"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2021-3618.json"}},{"package":{"name":"vsftpd","ecosystem":"Debian:12","purl":"pkg:deb/debian/vsftpd?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.0.3-13","3.0.3-13.1","3.0.5-0.1","3.0.5-0.2","3.0.5-0.3","3.0.5-0.4","3.0.5-0.5","3.0.5-0.6","3.0.5-0.7","3.0.5-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2021-3618.json"}},{"package":{"name":"vsftpd","ecosystem":"Debian:13","purl":"pkg:deb/debian/vsftpd?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.0.5-0.1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2021-3618.json"}},{"package":{"name":"vsftpd","ecosystem":"Debian:14","purl":"pkg:deb/debian/vsftpd?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.0.5-0.1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-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"}]}