Home/CVE/Envoy is an open source edge and service proxy, designed for cloud-native applications. The default_validator.cc impleme
CVE

CVE-2022-21656

Envoy is an open source edge and service proxy, designed for cloud-native applications. The default_validator.cc impleme

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.

HIGH · CVSS 7.4 EPSS 0.00016
Schedule remediation
  • CVSS base score ≥ 7.0
Sigma rules0 YARA rules0
⬡

Weakness Classification

CWE-295Improper Certificate Validation
CWE-843Access of Resource Using Incompatible Type ('Type Confusion')
▤

Affected Products & Versions

1
envoyproxy envoy< 1.20.2
▣

Scoring & Timeline

7.4
HIGH · CVSS v3.1 · security-advisories@github.com
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD22 Feb 2022 · 11:15 PM
CVSS VectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
SSVC triage · cisa-vulnrichment
Exploitation
none
Automatable
no
Technical impact
total
SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.
🔗

References & Sources

2
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://github.com/envoyproxy/envoy/commit/bb95af848c939cfe5b5ee33c5b1770558077e64ePatchThird Party Advisory
https://github.com/envoyproxy/envoy/security/advisories/GHSA-c9g7-xwcv-pjx2Issue TrackingThird Party Advisory
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