MEDIUM CVSS 5.3
Published: 2025-05-31

CVE-2025-4691

syntacticsinc easync Security Advisory (CVE-2025-4691)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2025-4691 impacting syntacticsinc easync. Evaluated with CVSS Base Score of 5.3 (MEDIUM).

Original NVD Description

Source: NIST NVD
The Free Booking Plugin for Hotels, Restaurants and Car Rentals – eaSYNC Booking plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 1.3.21 via the 'view_request_details' due to missing validation on a user controlled key. This makes it possible for unauthenticated attackers to view the details of any booking request. The vulnerability was partially patched in versions 1.3.18 and 1.3.21.

📊 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 syntacticsinc / easync
Affected Versions *
Weakness Enumeration CWE-639

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-2025-4691 impacting syntacticsinc easync.

⚡ Nuclei Detection Template (YAML) cve-2025-4691.yaml
id: cve-2025-4691

info:
  name: syntacticsinc easync - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2025-4691 affecting syntacticsinc easync.
    Evaluation: The Free Booking Plugin for Hotels, Restaurants and Car Rentals – eaSYNC Booking plugin for WordPress is vulnerable to Insecure Direct Object Referenc...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2025-4691
  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-2025-4691
    cwe-id: CWE-639
  tags: cve,cve-2025-4691,syntacticsinc,easync,medium

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "easync"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2025-4691.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2025-4691
# Target: syntacticsinc easync | 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-2025-4691 (syntacticsinc easync)...")
    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 syntacticsinc easync 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-2025-4691.sh
# Recommended Remediation & Patching Commands for CVE-2025-4691
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install easync 2>/dev/null || \
sudo dnf upgrade easync 2>/dev/null || \
sudo yum update easync

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

# 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-2025-4691 in syntacticsinc easync?

Review vendor-specific security notices and update syntacticsinc easync 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-2025-4691?

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-2025-4691?

CVE-2025-4691 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-2025-4691
Weakness CWE-639
Vendor syntacticsinc
Product easync
Published 2025-05-31
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N