HIGH CVSS 8.6
Published: 2021-03-19

CVE-2020-25097

squid-cache squid Security Advisory (CVE-2020-25097)
↗ Official NIST NVD Record
Seeking technical exploit breakdowns or verified PoC code for CVE-2020-25097?
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2020-25097 impacting squid-cache squid. Evaluated with CVSS Base Score of 8.6 (HIGH).

Original NVD Description

Source: NIST NVD
An issue was discovered in Squid through 4.13 and 5.x through 5.0.4. Due to improper input validation, it allows a trusted client to perform HTTP Request Smuggling and access services otherwise forbidden by the security controls. This occurs for certain uri_whitespace configuration settings.

📊 CVSS v3.1 Metric Breakdown

Attack Vector
Network (AV:N)
Exploitable remotely across internet boundaries
Attack Complexity
Low (AC:L)
No specialized conditions required
Privileges Required
None (PR:N)
Unauthenticated execution
User Interaction
None (UI:N)
Zero human interaction required
Scope
Changed (S:C)
Impacts components beyond caller authority
Confidentiality
High (C:H)
Total information disclosure
Integrity
None (I:N)
No system modification impact
Availability
None (A:N)
No system availability impact

🎯 Affected Versions Matrix

Affected Product squid-cache / squid
Affected Versions *
Weakness Enumeration CWE-20

Security Research Arsenal: Nuclei Detection Template & PoC Exploit Probe

High-Intent Research Tool

Ready-to-use security scanner signatures, active verification probe skeletons, and remediation playbooks for CVE-2020-25097 impacting squid-cache squid.

⚡ Nuclei Detection Template (YAML) cve-2020-25097.yaml
id: cve-2020-25097

info:
  name: squid-cache squid - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: high
  description: |
    Automated signature & scanner for CVE-2020-25097 affecting squid-cache squid.
    Evaluation: An issue was discovered in Squid through 4.13 and 5.x through 5.0.4. Due to improper input validation, it allows a trusted client to perform HTTP Requ...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2020-25097
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
    cvss-score: 8.6
    cve-id: CVE-2020-25097
    cwe-id: CWE-20
  tags: cve,cve-2020-25097,squid-cache,squid,high

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "squid"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2020-25097.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2020-25097
# Target: squid-cache squid | CVSS: 8.6 (HIGH)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2020-25097 (squid-cache squid)...")
    headers = {
        "User-Agent": "CyberVault-Audit-Scanner/2.0",
        "Accept": "*/*"
    }
    try:
        r = requests.get(f"{target_url.rstrip('/')}/", headers=headers, timeout=8, verify=False)
        print(f"[+] Server Response: HTTP {r.status_code} | Server Banner: {r.headers.get('Server', 'Unknown')}")
        if r.status_code < 500:
            print(f"[!] Target reachable. Verify version against squid-cache squid scope (*).")
        return True
    except Exception as e:
        print(f"[-] Connection Error: {e}")
        return False

if __name__ == '__main__':
    url = sys.argv[1] if len(sys.argv) > 1 else "http://localhost:8080"
    verify_vulnerability(url)
🛡️ Quick Patch & Remediation Script (Bash) patch_cve-2020-25097.sh
# Recommended Remediation & Patching Commands for CVE-2020-25097
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install squid 2>/dev/null || \
sudo dnf upgrade squid 2>/dev/null || \
sudo yum update squid

# 2. Inspect installed package versions for vulnerable scope:
dpkg -l | grep -i squid 2>/dev/null || rpm -qa | grep -i squid

# 3. Docker container & image vulnerability scan:
docker scan $(docker ps -q) 2>/dev/null || echo "Verify upstream base images in Dockerfile."

🛡️ Remediation & Security Action

  • Authoritative Guidance: Follow distribution-specific vendor security notices. Advisory status and package patches vary by distribution release.
  • Verification: Inspect installed binary packages and package manager versions for affected component releases.
  • Upstream Status: Upgrade to verified non-backdoored upstream versions or roll back to known-clean stable releases.
⚠️ Disclaimer: Follow vendor-specific advisories for your operating system. CyberVault does not fabricate unsupported remediation scripts.

❓ Frequently Asked Questions (FAQ) & Remediation Guide

How do I fix CVE-2020-25097 in squid-cache squid?

Review vendor-specific security notices and update squid-cache squid packages to the latest patched release immediately. If immediate upgrading is restricted by change windows, isolate affected network ports and enforce least-privilege access boundaries.

Is there an active exploit or public PoC for CVE-2020-25097?

No weaponized public exploit has been confirmed in public threat streams yet. Continuous surveillance is active across GitHub and security feeds.

What is the CVSS 3.1 severity rating and impact for CVE-2020-25097?

CVE-2020-25097 is classified with a CVSS 3.1 Base Score of 8.6 (HIGH). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
8.6
HIGH SEVERITY
CVE ID CVE-2020-25097
Weakness CWE-20
Vendor squid-cache
Product squid
Published 2021-03-19
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N