What is the CVSS score of CVE-2021-36371?

CVE-2021-36371 has a CVSS 3.1 base score of 3.7 (Low). CVSS vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N. EPSS exploitation probability: 0.7%.

Is there a public PoC exploit available for CVE-2021-36371?

Yes, a public proof-of-concept exploit is available for CVE-2021-36371. Prioritise patching immediately. EPSS: 0.7%.

Emissary Ingress CVE-2021-36371

LOW

Improper Certificate Validation (CWE-295)

2021-07-09 cve@mitre.org

Authentication Bypass Emissary Ingress

3.7

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

3.7 LOW

AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

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

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

Low

Availability

None

Lifecycle Timeline

CVE Published

Jul 09, 2021 - 21:15 nvd

LOW 3.7

DescriptionNVD

Emissary-Ingress (formerly Ambassador API Gateway) through 1.13.9 allows attackers to bypass client certificate requirements (i.e., mTLS cert_required) on backend upstreams when more than one TLSContext is defined and at least one configuration exists that does not require client certificate authentication. The attacker must send an SNI specifying an unprotected backend and an HTTP Host header specifying a protected backend. (2.x versions are unaffected. 1.x versions are unaffected with certain configuration settings involving prune_unreachable_routes and a wildcard Host resource.)

AnalysisAI

Emissary-Ingress (formerly Ambassador API Gateway) through 1.13.9 allows attackers to bypass client certificate requirements (i.e., mTLS cert_required) on backend upstreams when more than one. Rated low severity (CVSS 3.7), this vulnerability is remotely exploitable, no authentication required. Public exploit code available and no vendor patch available.

Technical ContextAI

This vulnerability is classified under CWE-295. Emissary-Ingress (formerly Ambassador API Gateway) through 1.13.9 allows attackers to bypass client certificate requirements (i.e., mTLS cert_required) on backend upstreams when more than one TLSContext is defined and at least one configuration exists that does not require client certificate authentication. The attacker must send an SNI specifying an unprotected backend and an HTTP Host header specifying a protected backend. (2.x versions are unaffected. 1.x versions are unaffected with certain configuration settings involving prune_unreachable_routes and a wildcard Host resource.) Affected products include: Getambassador Emissary-Ingress. Version information: through 1.13.9.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.