CVE-2021-3618

nginx: ALPACA is an application layer protocol content confusion attack, exploiting TLS servers implementing different proto...

CVE-2021-3618 is fixed in 55 products on 1 platform, first by libnginx-mod-http-auth-pam 1.14.0-0ubuntu1.10, released March 23, 2022. It is not reported as exploited. Patch Radar priority: High.

High
CVSS
7.4
high
Exploitation
None reported
No vendor assessment
CISA KEV
Not listed
Not in the Known Exploited Vulnerabilities catalog
EPSS
0.0203
81st percentile

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.

Where it's fixed

ProductFixed inFixReleased
Linux
libnginx-mod-http-auth-pam · Ubuntu 18.04.6 LTS (bionic) 1.14.0-0ubuntu1.10 libnginx-mod-http-auth-pam 1.14.0-0ubuntu1.10 Mar 23, 2022
libnginx-mod-http-auth-pam · Ubuntu 20.04 LTS (focal) 1.18.0-0ubuntu1.3 libnginx-mod-http-auth-pam 1.18.0-0ubuntu1.3 Mar 23, 2022
libnginx-mod-http-auth-pam · Ubuntu 22.04.1 LTS (jammy) 1.18.0-6ubuntu14.1 libnginx-mod-http-auth-pam 1.18.0-6ubuntu14.1 Mar 23, 2022
libnginx-mod-http-cache-purge · Ubuntu 18.04.6 LTS (bionic) 1.14.0-0ubuntu1.10 libnginx-mod-http-cache-purge 1.14.0-0ubuntu1.10 Mar 23, 2022
libnginx-mod-http-cache-purge · Ubuntu 20.04 LTS (focal) 1.18.0-0ubuntu1.3 libnginx-mod-http-cache-purge 1.18.0-0ubuntu1.3 Mar 23, 2022
libnginx-mod-http-cache-purge · Ubuntu 22.04.1 LTS (jammy) 1.18.0-6ubuntu14.1 libnginx-mod-http-cache-purge 1.18.0-6ubuntu14.1 Mar 23, 2022
libnginx-mod-http-dav-ext · Ubuntu 18.04.6 LTS (bionic) 1.14.0-0ubuntu1.10 libnginx-mod-http-dav-ext 1.14.0-0ubuntu1.10 Mar 23, 2022
libnginx-mod-http-dav-ext · Ubuntu 20.04 LTS (focal) 1.18.0-0ubuntu1.3 libnginx-mod-http-dav-ext 1.18.0-0ubuntu1.3 Mar 23, 2022
libnginx-mod-http-dav-ext · Ubuntu 22.04.1 LTS (jammy) 1.18.0-6ubuntu14.1 libnginx-mod-http-dav-ext 1.18.0-6ubuntu14.1 Mar 23, 2022
libnginx-mod-http-echo · Ubuntu 18.04.6 LTS (bionic) 1.14.0-0ubuntu1.10 libnginx-mod-http-echo 1.14.0-0ubuntu1.10 Mar 23, 2022
libnginx-mod-http-echo · Ubuntu 20.04 LTS (focal) 1.18.0-0ubuntu1.3 libnginx-mod-http-echo 1.18.0-0ubuntu1.3 Mar 23, 2022
libnginx-mod-http-echo · Ubuntu 22.04.1 LTS (jammy) 1.18.0-6ubuntu14.1 libnginx-mod-http-echo 1.18.0-6ubuntu14.1 Mar 23, 2022
libnginx-mod-http-fancyindex · Ubuntu 18.04.6 LTS (bionic) 1.14.0-0ubuntu1.10 libnginx-mod-http-fancyindex 1.14.0-0ubuntu1.10 Mar 23, 2022
libnginx-mod-http-fancyindex · Ubuntu 20.04 LTS (focal) 1.18.0-0ubuntu1.3 libnginx-mod-http-fancyindex 1.18.0-0ubuntu1.3 Mar 23, 2022
libnginx-mod-http-fancyindex · Ubuntu 22.04.1 LTS (jammy) 1.18.0-6ubuntu14.1 libnginx-mod-http-fancyindex 1.18.0-6ubuntu14.1 Mar 23, 2022
libnginx-mod-http-geoip · Ubuntu 18.04.6 LTS (bionic) 1.14.0-0ubuntu1.10 libnginx-mod-http-geoip 1.14.0-0ubuntu1.10 Mar 23, 2022
libnginx-mod-http-geoip · Ubuntu 20.04 LTS (focal) 1.18.0-0ubuntu1.3 libnginx-mod-http-geoip 1.18.0-0ubuntu1.3 Mar 23, 2022
libnginx-mod-http-geoip · Ubuntu 22.04.1 LTS (jammy) 1.18.0-6ubuntu14.1 libnginx-mod-http-geoip 1.18.0-6ubuntu14.1 Mar 23, 2022
libnginx-mod-http-geoip2 · Ubuntu 20.04 LTS (focal) 1.18.0-0ubuntu1.3 libnginx-mod-http-geoip2 1.18.0-0ubuntu1.3 Mar 23, 2022
libnginx-mod-http-geoip2 · Ubuntu 22.04.1 LTS (jammy) 1.18.0-6ubuntu14.1 libnginx-mod-http-geoip2 1.18.0-6ubuntu14.1 Mar 23, 2022
libnginx-mod-http-headers-more-filter · Ubuntu 18.04.6 LTS (bionic) 1.14.0-0ubuntu1.10 libnginx-mod-http-headers-more-filter 1.14.0-0ubuntu1.10 Mar 23, 2022
libnginx-mod-http-headers-more-filter · Ubuntu 20.04 LTS (focal) 1.18.0-0ubuntu1.3 libnginx-mod-http-headers-more-filter 1.18.0-0ubuntu1.3 Mar 23, 2022
libnginx-mod-http-headers-more-filter · Ubuntu 22.04.1 LTS (jammy) 1.18.0-6ubuntu14.1 libnginx-mod-http-headers-more-filter 1.18.0-6ubuntu14.1 Mar 23, 2022
libnginx-mod-http-image-filter · Ubuntu 18.04.6 LTS (bionic) 1.14.0-0ubuntu1.10 libnginx-mod-http-image-filter 1.14.0-0ubuntu1.10 Mar 23, 2022
libnginx-mod-http-image-filter · Ubuntu 20.04 LTS (focal) 1.18.0-0ubuntu1.3 libnginx-mod-http-image-filter 1.18.0-0ubuntu1.3 Mar 23, 2022
libnginx-mod-http-image-filter · Ubuntu 22.04.1 LTS (jammy) 1.18.0-6ubuntu14.1 libnginx-mod-http-image-filter 1.18.0-6ubuntu14.1 Mar 23, 2022
libnginx-mod-http-lua · Ubuntu 18.04.6 LTS (bionic) 1.14.0-0ubuntu1.10 libnginx-mod-http-lua 1.14.0-0ubuntu1.10 Mar 23, 2022
libnginx-mod-http-lua · Ubuntu 20.04 LTS (focal) 1.18.0-0ubuntu1.3 libnginx-mod-http-lua 1.18.0-0ubuntu1.3 Mar 23, 2022
libnginx-mod-http-ndk · Ubuntu 18.04.6 LTS (bionic) 1.14.0-0ubuntu1.10 libnginx-mod-http-ndk 1.14.0-0ubuntu1.10 Mar 23, 2022
libnginx-mod-http-ndk · Ubuntu 20.04 LTS (focal) 1.18.0-0ubuntu1.3 libnginx-mod-http-ndk 1.18.0-0ubuntu1.3 Mar 23, 2022
libnginx-mod-http-ndk · Ubuntu 22.04.1 LTS (jammy) 1.18.0-6ubuntu14.1 libnginx-mod-http-ndk 1.18.0-6ubuntu14.1 Mar 23, 2022
libnginx-mod-http-perl · Ubuntu 18.04.6 LTS (bionic) 1.14.0-0ubuntu1.10 libnginx-mod-http-perl 1.14.0-0ubuntu1.10 Mar 23, 2022
libnginx-mod-http-perl · Ubuntu 20.04 LTS (focal) 1.18.0-0ubuntu1.3 libnginx-mod-http-perl 1.18.0-0ubuntu1.3 Mar 23, 2022
libnginx-mod-http-perl · Ubuntu 22.04.1 LTS (jammy) 1.18.0-6ubuntu14.1 libnginx-mod-http-perl 1.18.0-6ubuntu14.1 Mar 23, 2022
libnginx-mod-http-subs-filter · Ubuntu 18.04.6 LTS (bionic) 1.14.0-0ubuntu1.10 libnginx-mod-http-subs-filter 1.14.0-0ubuntu1.10 Mar 23, 2022
libnginx-mod-http-subs-filter · Ubuntu 20.04 LTS (focal) 1.18.0-0ubuntu1.3 libnginx-mod-http-subs-filter 1.18.0-0ubuntu1.3 Mar 23, 2022
libnginx-mod-http-subs-filter · Ubuntu 22.04.1 LTS (jammy) 1.18.0-6ubuntu14.1 libnginx-mod-http-subs-filter 1.18.0-6ubuntu14.1 Mar 23, 2022
libnginx-mod-http-uploadprogress · Ubuntu 18.04.6 LTS (bionic) 1.14.0-0ubuntu1.10 libnginx-mod-http-uploadprogress 1.14.0-0ubuntu1.10 Mar 23, 2022
libnginx-mod-http-uploadprogress · Ubuntu 20.04 LTS (focal) 1.18.0-0ubuntu1.3 libnginx-mod-http-uploadprogress 1.18.0-0ubuntu1.3 Mar 23, 2022
libnginx-mod-http-uploadprogress · Ubuntu 22.04.1 LTS (jammy) 1.18.0-6ubuntu14.1 libnginx-mod-http-uploadprogress 1.18.0-6ubuntu14.1 Mar 23, 2022
libnginx-mod-http-upstream-fair · Ubuntu 18.04.6 LTS (bionic) 1.14.0-0ubuntu1.10 libnginx-mod-http-upstream-fair 1.14.0-0ubuntu1.10 Mar 23, 2022
libnginx-mod-http-upstream-fair · Ubuntu 20.04 LTS (focal) 1.18.0-0ubuntu1.3 libnginx-mod-http-upstream-fair 1.18.0-0ubuntu1.3 Mar 23, 2022
libnginx-mod-http-upstream-fair · Ubuntu 22.04.1 LTS (jammy) 1.18.0-6ubuntu14.1 libnginx-mod-http-upstream-fair 1.18.0-6ubuntu14.1 Mar 23, 2022
libnginx-mod-http-xslt-filter · Ubuntu 18.04.6 LTS (bionic) 1.14.0-0ubuntu1.10 libnginx-mod-http-xslt-filter 1.14.0-0ubuntu1.10 Mar 23, 2022
libnginx-mod-http-xslt-filter · Ubuntu 20.04 LTS (focal) 1.18.0-0ubuntu1.3 libnginx-mod-http-xslt-filter 1.18.0-0ubuntu1.3 Mar 23, 2022
libnginx-mod-http-xslt-filter · Ubuntu 22.04.1 LTS (jammy) 1.18.0-6ubuntu14.1 libnginx-mod-http-xslt-filter 1.18.0-6ubuntu14.1 Mar 23, 2022
libnginx-mod-mail · Ubuntu 18.04.6 LTS (bionic) 1.14.0-0ubuntu1.10 libnginx-mod-mail 1.14.0-0ubuntu1.10 Mar 23, 2022
libnginx-mod-mail · Ubuntu 20.04 LTS (focal) 1.18.0-0ubuntu1.3 libnginx-mod-mail 1.18.0-0ubuntu1.3 Mar 23, 2022
libnginx-mod-mail · Ubuntu 22.04.1 LTS (jammy) 1.18.0-6ubuntu14.1 libnginx-mod-mail 1.18.0-6ubuntu14.1 Mar 23, 2022
libnginx-mod-nchan · Ubuntu 18.04.6 LTS (bionic) 1.14.0-0ubuntu1.10 libnginx-mod-nchan 1.14.0-0ubuntu1.10 Mar 23, 2022
libnginx-mod-nchan · Ubuntu 20.04 LTS (focal) 1.18.0-0ubuntu1.3 libnginx-mod-nchan 1.18.0-0ubuntu1.3 Mar 23, 2022
libnginx-mod-nchan · Ubuntu 22.04.1 LTS (jammy) 1.18.0-6ubuntu14.1 libnginx-mod-nchan 1.18.0-6ubuntu14.1 Mar 23, 2022
libnginx-mod-rtmp · Ubuntu 18.04.6 LTS (bionic) 1.14.0-0ubuntu1.10 libnginx-mod-rtmp 1.14.0-0ubuntu1.10 Mar 23, 2022
libnginx-mod-rtmp · Ubuntu 20.04 LTS (focal) 1.18.0-0ubuntu1.3 libnginx-mod-rtmp 1.18.0-0ubuntu1.3 Mar 23, 2022
libnginx-mod-rtmp · Ubuntu 22.04.1 LTS (jammy) 1.18.0-6ubuntu14.1 libnginx-mod-rtmp 1.18.0-6ubuntu14.1 Mar 23, 2022
libnginx-mod-stream · Ubuntu 18.04.6 LTS (bionic) 1.14.0-0ubuntu1.10 libnginx-mod-stream 1.14.0-0ubuntu1.10 Mar 23, 2022
libnginx-mod-stream · Ubuntu 20.04 LTS (focal) 1.18.0-0ubuntu1.3 libnginx-mod-stream 1.18.0-0ubuntu1.3 Mar 23, 2022
libnginx-mod-stream · Ubuntu 22.04.1 LTS (jammy) 1.18.0-6ubuntu14.1 libnginx-mod-stream 1.18.0-6ubuntu14.1 Mar 23, 2022
libnginx-mod-stream-geoip · Ubuntu 22.04.1 LTS (jammy) 1.18.0-6ubuntu14.1 libnginx-mod-stream-geoip 1.18.0-6ubuntu14.1 Mar 23, 2022
libnginx-mod-stream-geoip2 · Ubuntu 22.04.1 LTS (jammy) 1.18.0-6ubuntu14.1 libnginx-mod-stream-geoip2 1.18.0-6ubuntu14.1 Mar 23, 2022
nginx · Debian 12.15 (bookworm) 1.20.2-2 DEBIAN-CVE-2021-3618 Mar 23, 2022
nginx · Debian 13.5 (trixie) 1.20.2-2 DEBIAN-CVE-2021-3618 Mar 23, 2022
nginx · Debian 14 1.20.2-2 DEBIAN-CVE-2021-3618 Mar 23, 2022
nginx · Ubuntu 18.04.6 LTS (bionic) 1.14.0-0ubuntu1.10 nginx 1.14.0-0ubuntu1.10 Mar 23, 2022
nginx · Ubuntu 20.04 LTS (focal) 1.18.0-0ubuntu1.3 nginx 1.18.0-0ubuntu1.3 Mar 23, 2022
nginx · Ubuntu 22.04.1 LTS (jammy) 1.18.0-6ubuntu14.1 nginx 1.18.0-6ubuntu14.1 Mar 23, 2022
nginx · amzn 2023 1:1.22.1-1.amzn2023.0.2 ALAS2023-2023-099 Feb 17, 2023
nginx-all-modules · amzn 2023 1:1.22.1-1.amzn2023.0.2 ALAS2023-2023-099 Feb 17, 2023
nginx-common · Ubuntu 18.04.6 LTS (bionic) 1.14.0-0ubuntu1.10 nginx-common 1.14.0-0ubuntu1.10 Mar 23, 2022
nginx-common · Ubuntu 20.04 LTS (focal) 1.18.0-0ubuntu1.3 nginx-common 1.18.0-0ubuntu1.3 Mar 23, 2022
nginx-common · Ubuntu 22.04.1 LTS (jammy) 1.18.0-6ubuntu14.1 nginx-common 1.18.0-6ubuntu14.1 Mar 23, 2022
nginx-core · Ubuntu 18.04.6 LTS (bionic) 1.14.0-0ubuntu1.10 nginx-core 1.14.0-0ubuntu1.10 Mar 23, 2022
nginx-core · Ubuntu 20.04 LTS (focal) 1.18.0-0ubuntu1.3 nginx-core 1.18.0-0ubuntu1.3 Mar 23, 2022
nginx-core · Ubuntu 22.04.1 LTS (jammy) 1.18.0-6ubuntu14.1 nginx-core 1.18.0-6ubuntu14.1 Mar 23, 2022
nginx-core · amzn 2023 1:1.22.1-1.amzn2023.0.2 ALAS2023-2023-099 Feb 17, 2023
nginx-core-debuginfo · amzn 2023 1:1.22.1-1.amzn2023.0.2 ALAS2023-2023-099 Feb 17, 2023
nginx-debuginfo · amzn 2023 1:1.22.1-1.amzn2023.0.2 ALAS2023-2023-099 Feb 17, 2023
nginx-debugsource · amzn 2023 1:1.22.1-1.amzn2023.0.2 ALAS2023-2023-099 Feb 17, 2023
nginx-extras · Ubuntu 18.04.6 LTS (bionic) 1.14.0-0ubuntu1.10 nginx-extras 1.14.0-0ubuntu1.10 Mar 23, 2022
nginx-extras · Ubuntu 20.04 LTS (focal) 1.18.0-0ubuntu1.3 nginx-extras 1.18.0-0ubuntu1.3 Mar 23, 2022
nginx-extras · Ubuntu 22.04.1 LTS (jammy) 1.18.0-6ubuntu14.1 nginx-extras 1.18.0-6ubuntu14.1 Mar 23, 2022
nginx-filesystem · amzn 2023 1:1.22.1-1.amzn2023.0.2 ALAS2023-2023-099 Feb 17, 2023
nginx-full · Ubuntu 18.04.6 LTS (bionic) 1.14.0-0ubuntu1.10 nginx-full 1.14.0-0ubuntu1.10 Mar 23, 2022
nginx-full · Ubuntu 20.04 LTS (focal) 1.18.0-0ubuntu1.3 nginx-full 1.18.0-0ubuntu1.3 Mar 23, 2022
nginx-full · Ubuntu 22.04.1 LTS (jammy) 1.18.0-6ubuntu14.1 nginx-full 1.18.0-6ubuntu14.1 Mar 23, 2022
nginx-light · Ubuntu 18.04.6 LTS (bionic) 1.14.0-0ubuntu1.10 nginx-light 1.14.0-0ubuntu1.10 Mar 23, 2022
nginx-light · Ubuntu 20.04 LTS (focal) 1.18.0-0ubuntu1.3 nginx-light 1.18.0-0ubuntu1.3 Mar 23, 2022
nginx-light · Ubuntu 22.04.1 LTS (jammy) 1.18.0-6ubuntu14.1 nginx-light 1.18.0-6ubuntu14.1 Mar 23, 2022
nginx-mod-devel · amzn 2023 1:1.22.1-1.amzn2023.0.2 ALAS2023-2023-099 Feb 17, 2023
nginx-mod-http-image-filter · amzn 2023 1:1.22.1-1.amzn2023.0.2 ALAS2023-2023-099 Feb 17, 2023
nginx-mod-http-image-filter-debuginfo · amzn 2023 1:1.22.1-1.amzn2023.0.2 ALAS2023-2023-099 Feb 17, 2023
nginx-mod-http-perl · amzn 2023 1:1.22.1-1.amzn2023.0.2 ALAS2023-2023-099 Feb 17, 2023
nginx-mod-http-perl-debuginfo · amzn 2023 1:1.22.1-1.amzn2023.0.2 ALAS2023-2023-099 Feb 17, 2023
nginx-mod-http-xslt-filter · amzn 2023 1:1.22.1-1.amzn2023.0.2 ALAS2023-2023-099 Feb 17, 2023
nginx-mod-http-xslt-filter-debuginfo · amzn 2023 1:1.22.1-1.amzn2023.0.2 ALAS2023-2023-099 Feb 17, 2023
nginx-mod-mail · amzn 2023 1:1.22.1-1.amzn2023.0.2 ALAS2023-2023-099 Feb 17, 2023
nginx-mod-mail-debuginfo · amzn 2023 1:1.22.1-1.amzn2023.0.2 ALAS2023-2023-099 Feb 17, 2023
nginx-mod-stream · amzn 2023 1:1.22.1-1.amzn2023.0.2 ALAS2023-2023-099 Feb 17, 2023
nginx-mod-stream-debuginfo · amzn 2023 1:1.22.1-1.amzn2023.0.2 ALAS2023-2023-099 Feb 17, 2023
sendmail · Debian 12.15 (bookworm) 8.16.1-2 DEBIAN-CVE-2021-3618 Mar 23, 2022
sendmail · Debian 13.5 (trixie) 8.16.1-2 DEBIAN-CVE-2021-3618 Mar 23, 2022
sendmail · Debian 14 8.16.1-2 DEBIAN-CVE-2021-3618 Mar 23, 2022
sendmail · amzn 2023 8.17.1-5.amzn2023.0.4 ALAS2023-2023-018 Feb 17, 2023
sendmail-cf · amzn 2023 8.17.1-5.amzn2023.0.4 ALAS2023-2023-018 Feb 17, 2023
sendmail-debuginfo · amzn 2023 8.17.1-5.amzn2023.0.4 ALAS2023-2023-018 Feb 17, 2023
sendmail-debugsource · amzn 2023 8.17.1-5.amzn2023.0.4 ALAS2023-2023-018 Feb 17, 2023
sendmail-doc · amzn 2023 8.17.1-5.amzn2023.0.4 ALAS2023-2023-018 Feb 17, 2023
sendmail-milter · amzn 2023 8.17.1-5.amzn2023.0.4 ALAS2023-2023-018 Feb 17, 2023
sendmail-milter-debuginfo · amzn 2023 8.17.1-5.amzn2023.0.4 ALAS2023-2023-018 Feb 17, 2023
sendmail-milter-devel · amzn 2023 8.17.1-5.amzn2023.0.4 ALAS2023-2023-018 Feb 17, 2023
vsftpd · Debian 13.5 (trixie) 3.0.5-0.1 DEBIAN-CVE-2021-3618 Mar 23, 2022
vsftpd · Debian 14 3.0.5-0.1 DEBIAN-CVE-2021-3618 Mar 23, 2022
vsftpd · Ubuntu 20.04 LTS (focal) 3.0.5-0ubuntu0.20.04.1 vsftpd 3.0.5-0ubuntu0.20.04.1 Mar 23, 2022
vsftpd · amzn 2023 3.0.5-1.amzn2023.0.2 ALAS2023-2023-019 Feb 17, 2023
vsftpd-debuginfo · amzn 2023 3.0.5-1.amzn2023.0.2 ALAS2023-2023-019 Feb 17, 2023
vsftpd-debugsource · amzn 2023 3.0.5-1.amzn2023.0.2 ALAS2023-2023-019 Feb 17, 2023

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