MEDIUM CVSS 5.3
Published: 2021-01-07

CVE-2018-18689

avanquest expert_pdf_ultimate Security Advisory (CVE-2018-18689)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2018-18689 impacting avanquest expert_pdf_ultimate. Evaluated with CVSS Base Score of 5.3 (MEDIUM).

Original NVD Description

Source: NIST NVD
The Portable Document Format (PDF) specification does not provide any information regarding the concrete procedure of how to validate signatures. Consequently, a Signature Wrapping vulnerability exists in multiple products. An attacker can use /ByteRange and xref manipulations that are not detected by the signature-validation logic. This affects Foxit Reader before 9.4 and PhantomPDF before 8.3.9 and 9.x before 9.4. It also affects eXpert PDF 12 Ultimate, Expert PDF Reader, Nitro Pro, Nitro Reader, PDF Architect 6, PDF Editor 6 Pro, PDF Experte 9 Ultimate, PDFelement6 Pro, PDF Studio Viewer 2018, PDF Studio Pro, PDF-XChange Editor and Viewer, Perfect PDF 10 Premium, Perfect PDF Reader, Soda PDF, and Soda PDF Desktop.

📊 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
Low (C:L)
Partial information leakage
Integrity
None (I:N)
No system modification impact
Availability
None (A:N)
No system availability impact

🎯 Affected Versions Matrix

Affected Product avanquest / expert_pdf_ultimate
Affected Versions 12.0.20
Weakness Enumeration CWE-347

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-2018-18689 impacting avanquest expert_pdf_ultimate.

⚡ Nuclei Detection Template (YAML) cve-2018-18689.yaml
id: cve-2018-18689

info:
  name: avanquest expert_pdf_ultimate - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2018-18689 affecting avanquest expert_pdf_ultimate.
    Evaluation: The Portable Document Format (PDF) specification does not provide any information regarding the concrete procedure of how to validate signatures. Cons...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2018-18689
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
    cvss-score: 5.3
    cve-id: CVE-2018-18689
    cwe-id: CWE-347
  tags: cve,cve-2018-18689,avanquest,expert_pdf_ultimate,medium

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "expert_pdf_ultimate"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2018-18689.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2018-18689
# Target: avanquest expert_pdf_ultimate | 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-2018-18689 (avanquest expert_pdf_ultimate)...")
    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 avanquest expert_pdf_ultimate scope (12.0.20).")
        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-2018-18689.sh
# Recommended Remediation & Patching Commands for CVE-2018-18689
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install expert_pdf_ultimate 2>/dev/null || \
sudo dnf upgrade expert_pdf_ultimate 2>/dev/null || \
sudo yum update expert_pdf_ultimate

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

# 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-2018-18689 in avanquest expert_pdf_ultimate?

Review vendor-specific security notices and update avanquest expert_pdf_ultimate 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-2018-18689?

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-2018-18689?

CVE-2018-18689 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-2018-18689
Weakness CWE-347
Vendor avanquest
Product expert_pdf_ultimate
Published 2021-01-07
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N