Vulnerability Report

CVE-2022-21657

Title: Envoy trusts certificates without proper extendedKeyUsage

Trust Bypass

Proof Of Concept

No public PoC currently indexed for CVE-2022-21657.

CWE Category CWE-295
Published Date Feb 22, 2022
Modified Date Nov 21, 2024
Exploit Status Not Found
Score 6.8 CVSS v3.1
Exploit Probability (EPSS)
0.52%

Vulnerability Summary

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.

CVSS v3.1
Source Entity [email protected]
Severity MEDIUM
6.8
Attack Vector
NETWORK
Complexity
HIGH
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N
CVSS v3.1
Source Entity [email protected]
Severity MEDIUM
6.5
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
CVSS v2.0
Source Entity [email protected]
Severity MEDIUM
4.0
Access Vector
N/A
Authentication
N/A
RAW VECTOR AV:N/AC:L/Au:S/C:N/I:P/A:N

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2022-21657 Exploits & PoCs (Proof Of Concept)

No public PoCs found in our database for this CVE.

MODIFIED

Vulnerability data or affected products updated.

PUBLISHED

Vulnerability first announced in NVD.

Attack Vector Matrix

Access Vector NETWORK
Complexity HIGH
Privileges N/A
Interaction NONE
CVSS Vector String CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N

Affected Stack

No specific products linked.