---
cve: "CVE-2022-21656"
severity: "HIGH"
cvss: 7.4
epss: "0.7%"
vendor: "envoyproxy"
kev: false
exploited: false
published: "2022-02-22 23:15:11"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-25T05:33:43+02:00"
---

# CVE-2022-21656

> 7.4 HIGH · 🧪 PoC

## Beschreibung

Envoy is an open source edge and service proxy, designed for cloud-native applications. The default_validator.cc implementation used to implement the default certificate validation routines has a "type confusion" bug when processing subjectAltNames. This processing allows, for example, an rfc822Name or uniformResourceIndicator to be authenticated as a domain name. This confusion allows for the bypassing of nameConstraints, as processed by the underlying OpenSSL/BoringSSL implementation, exposing the possibility of impersonation of arbitrary servers. As a result Envoy will trust upstream certificates that should not be trusted.

## CVSS-Vektor

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

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Hoch | good |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Hoch | bad |
| I Integrität | Hoch | bad |
| A Verfügbarkeit | Keine | good |

## Patch verfügbar (OSV)

- 4aaf9593152c6996b9da384c8918e9ad4f0abd4d (Commit)
- bb95af848c939cfe5b5ee33c5b1770558077e64e (Commit)

## Referenzen

- <https://github.com/envoyproxy/envoy/security/advisories/GHSA-c9g7-xwcv-pjx2>
- <https://github.com/envoyproxy/envoy/commit/bb95af848c939cfe5b5ee33c5b1770558077e64e>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2022-21656) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_