UNKNOWN CVSS 5.0
Published: 2009-05-22

CVE-2009-1755

nlnetlabs nsd Security Advisory (CVE-2009-1755)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2009-1755 impacting nlnetlabs nsd. Evaluated with CVSS Base Score of 5.0 (UNKNOWN).

Original NVD Description

Source: NIST NVD
Off-by-one error in the packet_read_query_section function in packet.c in nsd 3.2.1, and process_query_section in query.c in nsd 2.3.7, allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via unspecified vectors that trigger a buffer overflow.

📊 CVSS v3.1 Metric Breakdown

Attack Vector
Network (AV:N)
Exploitable remotely across internet boundaries
Attack Complexity
Low (AC:L)
No specialized conditions required
Confidentiality
None (C:N)
No data confidentiality impact
Integrity
None (I:N)
No system modification impact

🎯 Affected Versions Matrix

Affected Product nlnetlabs / nsd
Affected Versions 2.0.0
Weakness Enumeration CWE-189

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-2009-1755 impacting nlnetlabs nsd.

⚡ Nuclei Detection Template (YAML) cve-2009-1755.yaml
id: cve-2009-1755

info:
  name: nlnetlabs nsd - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: unknown
  description: |
    Automated signature & scanner for CVE-2009-1755 affecting nlnetlabs nsd.
    Evaluation: Off-by-one error in the packet_read_query_section function in packet.c in nsd 3.2.1, and process_query_section in query.c in nsd 2.3.7, allows remote ...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2009-1755
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/Au:N/C:N/I:N/A:P
    cvss-score: 5.0
    cve-id: CVE-2009-1755
    cwe-id: CWE-189
  tags: cve,cve-2009-1755,nlnetlabs,nsd,unknown

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "nsd"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2009-1755.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2009-1755
# Target: nlnetlabs nsd | CVSS: 5.0 (UNKNOWN)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2009-1755 (nlnetlabs nsd)...")
    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 nlnetlabs nsd scope (2.0.0).")
        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-2009-1755.sh
# Recommended Remediation & Patching Commands for CVE-2009-1755
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install nsd 2>/dev/null || \
sudo dnf upgrade nsd 2>/dev/null || \
sudo yum update nsd

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

# 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-2009-1755 in nlnetlabs nsd?

Review vendor-specific security notices and update nlnetlabs nsd 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-2009-1755?

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-2009-1755?

CVE-2009-1755 is classified with a CVSS 3.1 Base Score of 5.0 (UNKNOWN). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
5.0
UNKNOWN SEVERITY
CVE ID CVE-2009-1755
Weakness CWE-189
Vendor nlnetlabs
Product nsd
Published 2009-05-22
Vector AV:N/AC:L/Au:N/C:N/I:N/A:P