HIGH CVSS 7.5
Published: 2021-01-13

CVE-2020-5686

nec univerge_sv9500_firmware Security Advisory (CVE-2020-5686)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2020-5686 impacting nec univerge_sv9500_firmware. Evaluated with CVSS Base Score of 7.5 (HIGH).

Original NVD Description

Source: NIST NVD
Incorrect implementation of authentication algorithm issue in UNIVERGE SV9500 series from V1 to V7and SV8500 series from S6 to S8 allows an attacker to access the remote system maintenance feature and obtain the information by sending a specially crafted request to a specific URL.

📊 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
Unchanged (S:U)
Confined to same security context
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 nec / univerge_sv9500_firmware
Affected Versions *
Weakness Enumeration CWE-287

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-2020-5686 impacting nec univerge_sv9500_firmware.

⚡ Nuclei Detection Template (YAML) cve-2020-5686.yaml
id: cve-2020-5686

info:
  name: nec univerge_sv9500_firmware - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: high
  description: |
    Automated signature & scanner for CVE-2020-5686 affecting nec univerge_sv9500_firmware.
    Evaluation: Incorrect implementation of authentication algorithm issue in UNIVERGE SV9500 series from V1 to V7and SV8500 series from S6 to S8 allows an attacker t...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2020-5686
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
    cvss-score: 7.5
    cve-id: CVE-2020-5686
    cwe-id: CWE-287
  tags: cve,cve-2020-5686,nec,univerge_sv9500_firmware,high

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "univerge_sv9500_firmware"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2020-5686.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2020-5686
# Target: nec univerge_sv9500_firmware | CVSS: 7.5 (HIGH)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2020-5686 (nec univerge_sv9500_firmware)...")
    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 nec univerge_sv9500_firmware 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-2020-5686.sh
# Recommended Remediation & Patching Commands for CVE-2020-5686
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install univerge_sv9500_firmware 2>/dev/null || \
sudo dnf upgrade univerge_sv9500_firmware 2>/dev/null || \
sudo yum update univerge_sv9500_firmware

# 2. Inspect installed package versions for vulnerable scope:
dpkg -l | grep -i univerge_sv9500_firmware 2>/dev/null || rpm -qa | grep -i univerge_sv9500_firmware

# 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

❓ Frequently Asked Questions (FAQ) & Remediation Guide

How do I fix CVE-2020-5686 in nec univerge_sv9500_firmware?

Review vendor-specific security notices and update nec univerge_sv9500_firmware 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-2020-5686?

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-2020-5686?

CVE-2020-5686 is classified with a CVSS 3.1 Base Score of 7.5 (HIGH). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
7.5
HIGH SEVERITY
CVE ID CVE-2020-5686
Weakness CWE-287
Vendor nec
Product univerge_sv9500_firmware
Published 2021-01-13
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N