CVE-2020-15104 TLS Validation Vulnerability in Envoy

2020-07-1422:05:14

CWE-346

GitHub_M

www.cve.org

CVSS3

4.6

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

REQUIRED

Scope

UNCHANGED

Confidentiality Impact

LOW

Integrity Impact

LOW

Availability Impact

NONE

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N

AI Score

5.8

Confidence

High

EPSS

0.001

Percentile

22.7%

JSON

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.

CNA Affected

[
  {
    "product": "envoy",
    "vendor": "envoyproxy",
    "versions": [
      {
        "status": "affected",
        "version": "< 1.12.6"
      },
      {
        "status": "affected",
        "version": ">= 1.13.0, < 1.13.4"
      },
      {
        "status": "affected",
        "version": ">= 1.14.0, < 1.14.4"
      }
    ]
  }
]