CVE-2020-15104

MEDIUM5.4EPSS 0.12%

TLS Validation Vulnerability in Envoy

Published: 3/6/2024Modified: 3/13/2026
Also known as:BIT-envoy-2020-15104

Description

In Envoy before versions 1.12.6, 1.13.4, 1.14.4, and 1.15.0 when validating TLS certificates, Envoy would incorrectly allow a wildcard DNS Subject Alternative Name apply to multiple subdomains. For example, with a SAN of *.example.com, Envoy would incorrectly allow nested.subdomain.example.com, when it should only allow subdomain.example.com. This defect applies to both validating a client TLS certificate in mTLS, and validating a server TLS certificate for upstream connections. This vulnerability is only applicable to situations where an untrusted entity can obtain a signed wildcard TLS certificate for a domain of which you only intend to trust a subdomain of. For example, if you intend to trust api.mysubdomain.example.com, and an untrusted actor can obtain a signed TLS certificate for *.example.com or *.com. Configurations are vulnerable if they use verify_subject_alt_name in any Envoy version, or if they use match_subject_alt_names in version 1.14 or later. This issue has been fixed in Envoy versions 1.12.6, 1.13.4, 1.14.4, 1.15.0.

Affected packages (1)

  • Bitnami/envoyfrom 0, < 1.12.6, >= 1.13.0, < 1.13.4, >= 1.14.0, < 1.14.4

CVSS scores

SourceVersionSeverityVector
osvCVSS 3.1MEDIUM5.4CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

References (2)