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.
[
{
"vendor": "n/a",
"product": "ALPACA",
"versions": [
{
"version": "vsftpd 3.0.4, nginx 1.21.0, sendmail 8.17",
"status": "affected"
}
]
}
]