CVE-2021-3618
Severity
7.4HIGH
EPSS
0.6%
top 30.10%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
Timeline
PublishedMar 23
Latest updateSep 18
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 t…
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:NExploitability: 2.2 | Impact: 5.2
Affected Packages8 packages
Also affects: Debian Linux 10.0, Fedora 33, 34, 35
Patches
🔴Vulnerability Details
5GHSA▶
GHSA-r9r5-jxp7-whr4: ALPACA is an application layer protocol content confusion attack, exploiting TLS servers implementing different protocols but using compatible certifi↗2022-03-24
OSV▶
CVE-2021-3618: ALPACA is an application layer protocol content confusion attack, exploiting TLS servers implementing different protocols but using compatible certifi↗2022-03-23
CVEList▶
CVE-2021-3618: ALPACA is an application layer protocol content confusion attack, exploiting TLS servers implementing different protocols but using compatible certifi↗2022-03-23
📋Vendor Advisories
6Microsoft▶
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↗2022-03-08
Red Hat▶
ALPACA: Application Layer Protocol Confusion - Analyzing and Mitigating Cracks in TLS Authentication↗2021-06-09