Vulnerability in Envoyproxy Envoy
CVE-2022-21657
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.
Vulnerability class: Improper Certificate Validation
EPSS: 0.005 (41.0th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N.
Affected products
- Envoyproxy Envoy — versions >= 1.20.0, < 1.20.2, >= 1.19.0, < 1.19.3, < 1.18.6
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Third Party Advisory, Issue Tracking)
- security-advisories@github.com (Patch, Third Party Advisory, x_refsource_MISC)
Frequently asked questions
- What is CVE-2022-21657?
- CVE-2022-21657 is a medium-severity vulnerability in Envoyproxy Envoy, classified under Improper Certificate Validation. CVSS score: 6.8/10. Published 2022-02-22.
- How severe is CVE-2022-21657?
- Medium severity. CVSS v3 base score is 6.8 out of 10.