CVE-2021-3618

HIGH severity · CVSS 7.4 · CWE-295

7.4CVSS HIGH

Summary

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.

Impact & exploitability

Attack vectorNetwork

Attack complexityHigh

Privileges requiredNone

User interactionNone

Confidentiality impactHigh

Integrity impactHigh

Availability impactNone

Exploit probability (EPSS)1%

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Affected products we track (1)

Nginx

Recommendation

Apply the vendor fix promptly. Open any affected product above for its exact safe version.

Official patch: https://bugzilla.redhat.com/show_bug.cgi?id=1975623 ↗

CVE-2021-3618

Summary

Impact & exploitability

Affected products we track (1)

Recommendation

Additional information