Skip to content
Fencer Vulns
medium 4.6

CVE-2020-15104 json

TLS Validation Vulnerability in Envoy

published 2020-07-14 6 y ago modified 2026-09-08 2 mo ago also BIT-envoy-2020-15104 , EUVD-2020-7219 , GHSA-w5f5-6qhq-hhrg

cvss
4.6
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 16%
public exploits
0
none known

Summary

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.

Patch / fix

  • bitnami envoy 1.12.6, 1.13.4, 1.14.4
  • envoyproxy envoy 1.12.6, 1.13.4, 1.14.4
  • servicemesh-proxy service mesh 1.1 1.1.5-1.el8

red hat advisories RHSA-2020:3090

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2020-15104 updated cvss 6.6

envoyproxy/envoy: incorrectly validates TLS certificates when using wildcards for DNS SAN's

  • Red Hat OpenShift Service Mesh 1.1 servicemesh-proxy 1.1.5-1.el8
    fixed: vendor fix RHSA-2020:3090

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.25% chance of exploitation in the next 30 days, higher than 16% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 4.6 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N
NVD 3.1 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
NVD 2.0 5.5 AV:N/AC:L/Au:S/C:P/I:P/A:N
OSV 3.1 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

Affected packages

ecosystem package affected fixed in
bitnami envoy
<1.12.6
>=1.13.0, <1.13.4
>=1.14.0, <1.14.4
1.12.6
1.13.4
1.14.4

Affected products

  • envoyproxy envoy

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.