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CVE-2022-21657

MEDIUMCVSS 6.5/10EPSS 0.51%

Last modified

CVE-2022-21657 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. 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). EPSS estimates a 0.51% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1
6.5/10

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

EPSS Probability
0.51%

39.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
EnvoyproxyEnvoy< 1.18.6
EnvoyproxyEnvoy>= 1.19.0, < 1.19.3
EnvoyproxyEnvoy>= 1.20.0, < 1.20.2

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is 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.
How severe is CVE-2022-21657?
CVE-2022-21657 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 0.51% probability of exploitation in the next 30 days.
How do I fix CVE-2022-21657?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2022-21657?

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Source: NVD / NIST