CVE-2022-21657
X.509 Extended Key Usage and Trust Purposes bypass in Envoy
- State
- Published
- Severity
- 6.8 Medium
- Published
- Feb 22, 2022
- Updated
- Apr 23, 2025
- Reserved
- Nov 16, 2021
Description
Envoy is an open source edge and service proxy, designed for cloud-native applications. In affected versions Envoy does not restrict the set of certificates it accepts from the peer, either as a TLS client or a TLS server, to only those certificates that contain the necessary extendedKeyUsage (id-kp-serverAuth and id-kp-clientAuth, respectively). This means that a peer may present an e-mail certificate (e.g. id-kp-emailProtection), either as a leaf certificate or as a CA in the chain, and it will be accepted for TLS. This is particularly bad when combined with the issue described in pull request #630, in that it allows a Web PKI CA that is intended only for use with S/MIME, and thus exempted from audit or supervision, to issue TLS certificates that will be accepted by Envoy. As a result Envoy will trust upstream certificates that should not be trusted. There are no known workarounds to this issue. Users are advised to upgrade.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 6.8 Medium | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N | GitHub_M |
Weaknesses
- CWE-295 Improper Certificate Validation
Affected Products
| Product | Versions |
|---|---|
envoyenvoyproxy |
|
References
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