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.

• CVE ID
• CVE-2022-21657

• Assigner
• security-advisories@github.com

• Vulnerability Status
• Analyzed

• Published Version
• 2022-02-22T23:15:11

• Last Modified Date
• 2022-03-07T15:25:59

• Version
• 2.0

• Vector String
• AV:N/AC:L/Au:S/C:N/I:P/A:N

• Access Vector
• NETWORK

• Access Compatibility
• LOW

• Authentication
• SINGLE

• Confidentiality Impact
• NONE

• Integrity Impact
• PARTIAL

• Availability Impact
• NONE

• Base Score
• 4

• Severity
• MEDIUM

• Exploitability Score
• 8

• Impact Score
• 2.9

• Version
• 3.1

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

• Attack Vector
• NETWORK

• Attack Compatibility
• LOW

• Privileges Required
• LOW

• User Interaction
• NONE

• Scope
• UNCHANGED

• Confidentiality Impact
• NONE

• Availability Impact
• NONE

• Base Score
• 6.5

• Base Severity
• MEDIUM

• Exploitability Score
• 2.8

• Impact Score
• 3.6