What is the CVSS score of CVE-2020-37056?

CVE-2020-37056 has a CVSS 3.1 base score of 9.8 (Critical). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.0%.

Is there a public PoC exploit available for CVE-2020-37056?

Yes, a public proof-of-concept exploit is available for CVE-2020-37056. Prioritise patching immediately. EPSS: 0.0%.

How to fix or mitigate CVE-2020-37056?

Within 24 hours: Inventory all systems running Crystal Shard http-protection 0.2.0 and assess business criticality; implement WAF rules to detect/block spoofed IP headers and restrict header manipulation. Within 7 days: Deploy network segmentation to isolate affected systems from sensitive data; enable detailed logging on all http-protection middleware; establish incident response readiness. Within 30 days: Evaluate replacement middleware or upgrade to alternative security solutions; migrate off Crystal Shard http-protection 0.2.0; conduct security assessment of systems that may have been compromised during exposure period.

CVE-2020-37056

CRITICAL

Authentication Bypass by Spoofing (CWE-290)

2026-01-30 disclosure@vulncheck.com

Authentication Bypass

9.8

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

9.8 CRITICAL

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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 22:00 vuln.today

PoC Detected

Feb 03, 2026 - 16:44 vuln.today

Public exploit code

CVE Published

Jan 30, 2026 - 23:16 nvd

CRITICAL 9.8

DescriptionCVE.org

Crystal Shard http-protection 0.2.0 contains an IP spoofing vulnerability that allows attackers to bypass protection middleware by manipulating request headers. Attackers can hardcode consistent IP values across X-Forwarded-For, X-Client-IP, and X-Real-IP headers to circumvent security checks and gain unauthorized access.

AnalysisAI

IP spoofing vulnerability in Crystal Shard http-protection 0.2.0 allows attackers to bypass protection middleware by manipulating request headers. PoC available.

Technical ContextAI

CWE-290 authentication bypass via IP spoofing. HTTP middleware trusts client-supplied headers for IP identification.

Affected ProductsAI

Crystal Shard http-protection 0.2.0

RemediationAI

Update http-protection. Configure trusted proxy settings.

CVE-2020-37056 vulnerability details – vuln.today

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CVE-2020-37056

Severity by source

CVSS VectorNVD

Lifecycle Timeline

DescriptionCVE.org

AnalysisAI

Technical ContextAI

Affected ProductsAI

RemediationAI

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External POC / Exploit Code