CRITICAL CVSS 9.0
Published: 2020-12-24

CVE-2020-2503

qnap qes Security Advisory (CVE-2020-2503)
↗ Official NIST NVD Record
Seeking technical exploit breakdowns or verified PoC code for CVE-2020-2503?
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2020-2503 impacting qnap qes. Evaluated with CVSS Base Score of 9.0 (CRITICAL).

Original NVD Description

Source: NIST NVD
If exploited, this stored cross-site scripting vulnerability could allow remote attackers to inject malicious code in File Station. QNAP has already fixed these issues in QES 2.1.1 Build 20201006 and later.

📊 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
Low (PR:L)
Standard user access required
User Interaction
Required (UI:R)
User must click or open resource
Scope
Changed (S:C)
Impacts components beyond caller authority
Confidentiality
High (C:H)
Total information disclosure
Integrity
High (I:H)
Total modification of target system
Availability
High (A:H)
Total denial of service or shutdown

🎯 Affected Versions Matrix

Affected Product qnap / qes
Affected Versions *
Weakness Enumeration CWE-79

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-2020-2503 impacting qnap qes.

⚡ Nuclei Detection Template (YAML) cve-2020-2503.yaml
id: cve-2020-2503

info:
  name: qnap qes - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: critical
  description: |
    Automated signature & scanner for CVE-2020-2503 affecting qnap qes.
    Evaluation: If exploited, this stored cross-site scripting vulnerability could allow remote attackers to inject malicious code in File Station. QNAP has already f...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2020-2503
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H
    cvss-score: 9.0
    cve-id: CVE-2020-2503
    cwe-id: CWE-79
  tags: cve,cve-2020-2503,qnap,qes,critical

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "qes"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2020-2503.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2020-2503
# Target: qnap qes | CVSS: 9.0 (CRITICAL)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2020-2503 (qnap qes)...")
    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 qnap qes 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-2020-2503.sh
# Recommended Remediation & Patching Commands for CVE-2020-2503
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install qes 2>/dev/null || \
sudo dnf upgrade qes 2>/dev/null || \
sudo yum update qes

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

# 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.

🔗 Verified Technical References

Authorities
  • No records filed in this category.
Distributions
  • No records filed in this category.

❓ Frequently Asked Questions (FAQ) & Remediation Guide

How do I fix CVE-2020-2503 in qnap qes?

Review vendor-specific security notices and update qnap qes 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-2020-2503?

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-2020-2503?

CVE-2020-2503 is classified with a CVSS 3.1 Base Score of 9.0 (CRITICAL). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
9.0
CRITICAL SEVERITY
CVE ID CVE-2020-2503
Weakness CWE-79
Vendor qnap
Product qes
Published 2020-12-24
Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H