UNKNOWN CVSS 7.1
Published: 2012-09-14

CVE-2012-3955

isc dhcp Security Advisory (CVE-2012-3955)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2012-3955 impacting isc dhcp. Evaluated with CVSS Base Score of 7.1 (UNKNOWN).

Original NVD Description

Source: NIST NVD
ISC DHCP 4.1.x before 4.1-ESV-R7 and 4.2.x before 4.2.4-P2 allows remote attackers to cause a denial of service (daemon crash) in opportunistic circumstances by establishing an IPv6 lease in an environment where the lease expiration time is later reduced.

📊 CVSS v3.1 Metric Breakdown

Attack Vector
Network (AV:N)
Exploitable remotely across internet boundaries
Confidentiality
None (C:N)
No data confidentiality impact
Integrity
None (I:N)
No system modification impact

🎯 Affected Versions Matrix

Affected Product isc / dhcp
Affected Versions 4.1-esv
Weakness Enumeration NVD-CWE-noinfo

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-2012-3955 impacting isc dhcp.

⚡ Nuclei Detection Template (YAML) cve-2012-3955.yaml
id: cve-2012-3955

info:
  name: isc dhcp - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: unknown
  description: |
    Automated signature & scanner for CVE-2012-3955 affecting isc dhcp.
    Evaluation: ISC DHCP 4.1.x before 4.1-ESV-R7 and 4.2.x before 4.2.4-P2 allows remote attackers to cause a denial of service (daemon crash) in opportunistic circum...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2012-3955
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:M/Au:N/C:N/I:N/A:C
    cvss-score: 7.1
    cve-id: CVE-2012-3955
    cwe-id: NVD-CWE-noinfo
  tags: cve,cve-2012-3955,isc,dhcp,unknown

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "dhcp"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2012-3955.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2012-3955
# Target: isc dhcp | CVSS: 7.1 (UNKNOWN)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2012-3955 (isc dhcp)...")
    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 isc dhcp scope (4.1-esv).")
        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-2012-3955.sh
# Recommended Remediation & Patching Commands for CVE-2012-3955
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install dhcp 2>/dev/null || \
sudo dnf upgrade dhcp 2>/dev/null || \
sudo yum update dhcp

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

# 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-2012-3955 in isc dhcp?

Review vendor-specific security notices and update isc dhcp 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-2012-3955?

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-2012-3955?

CVE-2012-3955 is classified with a CVSS 3.1 Base Score of 7.1 (UNKNOWN). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
7.1
UNKNOWN SEVERITY
CVE ID CVE-2012-3955
Weakness NVD-CWE-noinfo
Vendor isc
Product dhcp
Published 2012-09-14
Vector AV:N/AC:M/Au:N/C:N/I:N/A:C