CVE-2021-3618
Published: August 31, 2023Last modified: August 31, 2023
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 score breakdown
| Parameter | Value |
|---|---|
| Base score | 7.4 |
| Attack Vector | NETWORK |
| Attack complexity | HIGH |
| Privileges required | NONE |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | HIGH |
| Integrity impact | HIGH |
| Availability impact | NONE |
| Vector | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | nginx | Not affected (1.22.1-r0) |
| Stream | nginx | Not affected (1.24.0-r11) |