CVE-2021-3618
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.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2021-3618
Vendor advisory: suse — https://www.suse.com/security/cve/CVE-2021-3618.html
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| arch | fixed | 1.21.0-1 | |
| sles | affected | | |
| debian | bookworm | fixed | 1.20.2-2 |
| debian | bullseye | fixed | 1.18.0-6.1+deb11u2 |
| debian | forky | fixed | 1.20.2-2 |
| debian | sid | fixed | 1.20.2-2 |
| debian | trixie | fixed | 1.20.2-2 |
References
Verify integrity in audit chain (admin only). AS-IS.