IP Spoofing Vulnerability in Crystal Shard http-protection by Rogerio Zambon
CVE-2020-37056

6.9MEDIUM

Key Information:

Vendor

Crystal Shard

Status
Http-protection
Vendor
CVE Published:
30 January 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2020-37056?

The Crystal Shard http-protection version 0.2.0 is susceptible to an IP spoofing vulnerability that enables attackers to manipulate request headers, specifically X-Forwarded-For, X-Client-IP, and X-Real-IP. By hardcoding uniform IP values across these headers, malicious actors can bypass essential security middleware, resulting in unauthorized access to sensitive resources or systems.

Affected Version(s)

http-protection <= 0.2.0

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2020-37056 - Proof of Concept

References

https://www.exploit-db.com/exploits/48533
exploit
https://github.com/rogeriozambon/http-protection
product
https://www.vulncheck.com/advisories/crystal-shard-http-p...
third-party-advisory

CVSS V4

Score:
6.9
Severity:
MEDIUM
Confidentiality:
None
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

Halis Duraki (@0xduraki)
.