Vulnerability CVE-2021-3618: Information

Description

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.

Severity: HIGH (7.4) Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Fixed packages

References to Advisories, Solutions, and Tools

1. Affected configurations:

   1. Configuration 1

      cpe:2.3:a:f5:nginx:*:*:*:*:*:*:*:*

      End excliding

      1.21.0

      ---

      Configuration 2

      cpe:2.3:a:sendmail:sendmail:*:*:*:*:*:*:*:*

      End excliding

      8.17

      ---

      Configuration 3

      cpe:2.3:a:vsftpd_project:vsftpd:*:*:*:*:*:*:*:*

      End excliding

      3.0.4

      ---

      Configuration 4

      cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*

      ---

      cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*

      ---

      cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*

      ---

      Configuration 5

      cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*

      ---