Medium severity · published Feb 22, 2022
CVE-2022-21656
Envoy is an open source edge and service proxy, designed for cloud-native applications
5.9
CVSS
0.7%
EPSS
No
On KEV
Description
Envoy is an open source edge and service proxy, designed for cloud-native applications. The default_validator.cc implementation used to implement the default certificate validation routines has a "type confusion" bug when processing subjectAltNames. This processing allows, for example, an rfc822Name or uniformResourceIndicator to be authenticated as a domain name. This confusion allows for the bypassing of nameConstraints, as processed by the underlying OpenSSL/BoringSSL implementation, exposing the possibility of impersonation of arbitrary servers. As a result Envoy will trust upstream certificates that should not be trusted.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
None
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.7% · higher than 52% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
EN
Envoy · Envoyproxy
before 1.20.2 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2022-21656
CVE.org
https://www.cve.org/CVERecord?id=CVE-2022-21656
Patch
https://github.com/envoyproxy/envoy/commit/bb95af848c939cfe5b5ee33c5b1770558077e64e
Issue Tracking
https://github.com/envoyproxy/envoy/security/advisories/GHSA-c9g7-xwcv-pjx2
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