MEDIUM CVSS 5.3
Published: 2021-03-18

CVE-2021-27656

johnsoncontrols exacqvision_web_service Security Advisory (CVE-2021-27656)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2021-27656 impacting johnsoncontrols exacqvision_web_service. Evaluated with CVSS Base Score of 5.3 (MEDIUM).

Original NVD Description

Source: NIST NVD
A vulnerability in exacqVision Web Service 20.12.2.0 and prior could allow an unauthenticated attacker to view system-level information about the exacqVision Web Service and the operating system.

📊 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
None (C:N)
No data confidentiality impact
Integrity
None (I:N)
No system modification impact
Availability
Low (A:L)
Partial service performance degradation

🎯 Affected Versions Matrix

Affected Product johnsoncontrols / exacqvision_web_service
Affected Versions *
Weakness Enumeration CWE-862

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-2021-27656 impacting johnsoncontrols exacqvision_web_service.

⚡ Nuclei Detection Template (YAML) cve-2021-27656.yaml
id: cve-2021-27656

info:
  name: johnsoncontrols exacqvision_web_service - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2021-27656 affecting johnsoncontrols exacqvision_web_service.
    Evaluation: A vulnerability in exacqVision Web Service 20.12.2.0 and prior could allow an unauthenticated attacker to view system-level information about the exac...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2021-27656
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
    cvss-score: 5.3
    cve-id: CVE-2021-27656
    cwe-id: CWE-862
  tags: cve,cve-2021-27656,johnsoncontrols,exacqvision_web_service,medium

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "exacqvision_web_service"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2021-27656.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2021-27656
# Target: johnsoncontrols exacqvision_web_service | CVSS: 5.3 (MEDIUM)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2021-27656 (johnsoncontrols exacqvision_web_service)...")
    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 johnsoncontrols exacqvision_web_service 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-2021-27656.sh
# Recommended Remediation & Patching Commands for CVE-2021-27656
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install exacqvision_web_service 2>/dev/null || \
sudo dnf upgrade exacqvision_web_service 2>/dev/null || \
sudo yum update exacqvision_web_service

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

# 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-2021-27656 in johnsoncontrols exacqvision_web_service?

Review vendor-specific security notices and update johnsoncontrols exacqvision_web_service 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-2021-27656?

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-2021-27656?

CVE-2021-27656 is classified with a CVSS 3.1 Base Score of 5.3 (MEDIUM). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
5.3
MEDIUM SEVERITY
CVE ID CVE-2021-27656
Weakness CWE-862
Vendor johnsoncontrols
Product exacqvision_web_service
Published 2021-03-18
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L