CRITICAL CVSS 9.8
Published: 2026-03-28

CVE-2017-20227

varaneckas jad_java_decompiler Security Advisory (CVE-2017-20227)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2017-20227 impacting varaneckas jad_java_decompiler. Evaluated with CVSS Base Score of 9.8 (CRITICAL).

Original NVD Description

Source: NIST NVD
JAD Java Decompiler 1.5.8e-1kali1 and prior contains a stack-based buffer overflow vulnerability that allows attackers to execute arbitrary code by supplying overly long input that exceeds buffer boundaries. Attackers can craft malicious input passed to the jad command to overflow the stack and execute a return-oriented programming chain that spawns a shell.

📊 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
High (I:H)
Total modification of target system
Availability
High (A:H)
Total denial of service or shutdown

🎯 Affected Versions Matrix

Affected Product varaneckas / jad_java_decompiler
Affected Versions 1.5.8e-1kali1
Weakness Enumeration CWE-787

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-2017-20227 impacting varaneckas jad_java_decompiler.

⚡ Nuclei Detection Template (YAML) cve-2017-20227.yaml
id: cve-2017-20227

info:
  name: varaneckas jad_java_decompiler - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: critical
  description: |
    Automated signature & scanner for CVE-2017-20227 affecting varaneckas jad_java_decompiler.
    Evaluation: JAD Java Decompiler 1.5.8e-1kali1 and prior contains a stack-based buffer overflow vulnerability that allows attackers to execute arbitrary code by su...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2017-20227
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    cvss-score: 9.8
    cve-id: CVE-2017-20227
    cwe-id: CWE-787
  tags: cve,cve-2017-20227,varaneckas,jad_java_decompiler,critical

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "jad_java_decompiler"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2017-20227.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2017-20227
# Target: varaneckas jad_java_decompiler | CVSS: 9.8 (CRITICAL)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2017-20227 (varaneckas jad_java_decompiler)...")
    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 varaneckas jad_java_decompiler scope (1.5.8e-1kali1).")
        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-2017-20227.sh
# Recommended Remediation & Patching Commands for CVE-2017-20227
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install jad_java_decompiler 2>/dev/null || \
sudo dnf upgrade jad_java_decompiler 2>/dev/null || \
sudo yum update jad_java_decompiler

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

# 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-2017-20227 in varaneckas jad_java_decompiler?

Review vendor-specific security notices and update varaneckas jad_java_decompiler 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-2017-20227?

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-2017-20227?

CVE-2017-20227 is classified with a CVSS 3.1 Base Score of 9.8 (CRITICAL). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
9.8
CRITICAL SEVERITY
CVE ID CVE-2017-20227
Weakness CWE-787
Vendor varaneckas
Product jad_java_decompiler
Published 2026-03-28
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H