Comprehensive Technical Analysis of EUVD-2023-42725 (CVE-2023-38965)

Lost and Found Information System 1.0 – Account Takeover via Insecure Direct Object Reference (IDOR)

1. Vulnerability Assessment & Severity Evaluation

Vulnerability Classification

EUVD-2023-42725 (CVE-2023-38965) is an Insecure Direct Object Reference (IDOR) vulnerability in the Lost and Found Information System 1.0, allowing unauthenticated attackers to perform account takeover via a crafted HTTP request to /classes/Users.php?f=save.

CVSS v3.1 Severity Breakdown

Metric	Value	Explanation
Attack Vector (AV)	Network (N)	Exploitable remotely over the internet.
Attack Complexity (AC)	Low (L)	No specialized conditions required.
Privileges Required (PR)	None (N)	No authentication needed.
User Interaction (UI)	None (N)	No user interaction required.
Scope (S)	Unchanged (U)	Impact is confined to the vulnerable system.
Confidentiality (C)	High (H)	Attacker gains full access to user accounts.
Integrity (I)	High (H)	Attacker can modify user data.
Availability (A)	High (H)	Potential for denial of service or system compromise.
Base Score	9.8 (Critical)	Aligns with CVSS v3.1 critical severity.

Risk Assessment

• Exploitability: High (public PoC available, low complexity).
• Impact: Severe (full account compromise, data manipulation, potential lateral movement).
• EPSS Score: 1.0 (100th percentile) – High likelihood of exploitation in the wild.

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2. Potential Attack Vectors & Exploitation Methods

Exploitation Mechanism

The vulnerability stems from improper access control in /classes/Users.php?f=save, where the application fails to validate whether a user is authorized to modify another user’s credentials.

Step-by-Step Exploitation:

1. Reconnaissance:

   • Attacker identifies the target system (e.g., via Shodan, Censys, or manual discovery).
   • Enumerates usernames (e.g., via /login.php error messages or default accounts).

2. Crafting the Exploit:

   • The attacker sends a POST request to /classes/Users.php?f=save with manipulated parameters:

     POST /classes/Users.php?f=save HTTP/1.1
     Host: target.example.com
     Content-Type: application/x-www-form-urlencoded
     
     id=[TARGET_USER_ID]&username=[ATTACKER_CONTROLLED_USERNAME]&password=[NEW_PASSWORD]
     

   • Key Parameters:
     • id: The victim’s user ID (e.g., 1 for admin).
     • username: Overwrites the victim’s username (optional).
     • password: Sets a new password for the victim’s account.

3. Account Takeover:

   • The system processes the request without authentication or authorization checks, allowing the attacker to:
     • Reset the victim’s password.
     • Gain full control over the account.
     • Escalate privileges if the victim is an administrator.

4. Post-Exploitation:

   • Access sensitive data (e.g., personal records, lost item details).
   • Modify or delete records.
   • Pivot to other systems if the compromised account has elevated privileges.

Proof-of-Concept (PoC) Availability

• GitHub Reference: Or4ngm4n’s Vulnerability Code Review
• Packet Storm Exploit: Lost And Found Information System 1.0 IDOR

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3. Affected Systems & Software Versions

Vulnerable Software

• Product: Lost and Found Information System
• Version: 1.0 (no patches available as of analysis)
• Vendor: Unspecified (ENISA records indicate "n/a")

Deployment Context

• Typically used by universities, public institutions, or corporate lost-and-found services.
• Often deployed in internal networks but may be exposed to the internet if misconfigured.

Detection Methods

• Manual Testing:
  • Send a POST request to /classes/Users.php?f=save with a valid id parameter.
  • Check if the system allows password changes without authentication.
• Automated Scanning:
  • Nuclei Template: CVE-2023-38965
  • Burp Suite / OWASP ZAP: Intercept and modify requests to /classes/Users.php.

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4. Recommended Mitigation Strategies

Immediate Actions

1. Temporary Workarounds:

   • Disable /classes/Users.php?f=save via web server rules (e.g., .htaccess or Nginx deny directives).
   • Rate-limit requests to sensitive endpoints.
   • Monitor logs for suspicious activity (e.g., repeated password reset attempts).

2. Permanent Fixes:

   • Implement Proper Authentication & Authorization:
     • Ensure all sensitive endpoints (e.g., /classes/Users.php) require session validation.
     • Use CSRF tokens to prevent unauthorized requests.
   • Input Validation & Sanitization:
     • Validate id parameters to ensure they belong to the authenticated user.
     • Use prepared statements to prevent SQL injection (if applicable).
   • Patch Management:
     • If an updated version is released, apply it immediately.
     • If no patch exists, consider migrating to a secure alternative (e.g., open-source lost-and-found systems with active maintenance).

3. Defensive Measures:

   • Web Application Firewall (WAF) Rules:
     • Block requests to /classes/Users.php?f=save unless they originate from trusted IPs.
     • Deploy ModSecurity OWASP Core Rule Set (CRS).
   • Network Segmentation:
     • Isolate the application in a DMZ or internal VLAN to limit exposure.
   • Multi-Factor Authentication (MFA):
     • Enforce MFA for all administrative accounts.

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5. Impact on the European Cybersecurity Landscape

Regulatory & Compliance Implications

• GDPR (General Data Protection Regulation):
  • Unauthorized access to personal data (e.g., lost item records) may constitute a data breach, requiring 72-hour notification to authorities (Art. 33 GDPR).
  • Fines of up to €20 million or 4% of global revenue (whichever is higher) may apply if negligence is proven.
• NIS2 Directive (Network and Information Security):
  • Critical infrastructure operators (e.g., universities, public services) must report significant incidents.
  • Failure to mitigate known vulnerabilities may result in regulatory penalties.

Threat Landscape in Europe

• Targeted Sectors:
  • Education (universities, schools).
  • Public Administration (municipal lost-and-found services).
  • Corporate (office lost-and-found systems).
• Exploitation Trends:
  • Ransomware Groups: May exploit IDOR vulnerabilities for initial access.
  • Cybercriminals: Could sell compromised accounts on dark web markets.
  • State-Sponsored Actors: May target public institutions for espionage.

ENISA & CERT-EU Recommendations

• ENISA Threat Landscape Report (2023): Highlights IDOR vulnerabilities as a top risk for web applications.
• CERT-EU Alerts: Advises organizations to patch or mitigate critical vulnerabilities within 14 days of disclosure.

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6. Technical Details for Security Professionals

Root Cause Analysis

The vulnerability exists due to:

1. Missing Authentication Check:
   • The /classes/Users.php?f=save endpoint does not verify if the requester is logged in.
2. Insecure Direct Object Reference (IDOR):
   • The id parameter is trusted without validation, allowing attackers to modify arbitrary accounts.
3. Lack of CSRF Protection:
   • No anti-CSRF tokens are implemented, enabling cross-site request forgery attacks.

Code-Level Vulnerability (Hypothetical Example)

// Vulnerable code snippet (simplified)
if ($_GET['f'] == 'save') {
    $id = $_POST['id'];
    $username = $_POST['username'];
    $password = md5($_POST['password']); // Weak hashing (MD5)

    $query = "UPDATE users SET username='$username', password='$password' WHERE id=$id";
    $conn->query($query); // No authentication check!
}

Issues:

• No session validation ($_SESSION check missing).
• No parameterized queries (SQL injection risk).
• Weak password hashing (MD5).

Exploitation Detection & Forensics

• Log Analysis:
  • Look for unauthenticated POST requests to /classes/Users.php?f=save.
  • Check for unusual password reset patterns (e.g., multiple resets in a short time).
• Indicators of Compromise (IoCs):
  • Unexpected changes in users table (e.g., password hashes).
  • New admin accounts created without authorization.
• Memory Forensics:
  • Check for unusual PHP processes (e.g., php-cgi with suspicious arguments).

Advanced Mitigation Techniques

• PHP-Specific Fixes:

  // Secure implementation example
  session_start();
  if (!isset($_SESSION['user_id']) || $_SESSION['user_id'] != $_POST['id']) {
      die("Unauthorized access");
  }
  
  $id = $conn->real_escape_string($_POST['id']); // Basic SQLi prevention
  $username = $conn->real_escape_string($_POST['username']);
  $password = password_hash($_POST['password'], PASSWORD_BCRYPT); // Secure hashing
  
  $stmt = $conn->prepare("UPDATE users SET username=?, password=? WHERE id=?");
  $stmt->bind_param("ssi", $username, $password, $id);
  $stmt->execute();
  

• Framework-Level Protections:
  • Use Laravel, Symfony, or CodeIgniter with built-in CSRF and ORM protections.
  • Implement role-based access control (RBAC).

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Conclusion & Recommendations

Key Takeaways

• Critical Severity (CVSS 9.8): Immediate action required.
• Public Exploits Available: High risk of mass exploitation.
• GDPR & NIS2 Compliance Risk: Organizations must mitigate or face regulatory penalties.

Action Plan for Security Teams

1. Immediate:
   • Patch or disable the vulnerable endpoint.
   • Audit logs for signs of exploitation.
2. Short-Term:
   • Deploy WAF rules to block malicious requests.
   • Enforce MFA for all administrative accounts.
3. Long-Term:
   • Migrate to a secure alternative if no patches are available.
   • Conduct a full application security review (SAST/DAST).

Reporting & Disclosure

• CERT-EU: Report incidents via https://cert.europa.eu.
• National CSIRTs: Contact local CERT (e.g., CERT-FR, CERT-DE, NCSC UK).

Final Note: Given the EPSS score of 1.0, this vulnerability is highly likely to be exploited in the wild. Organizations must act immediately to prevent account takeovers and data breaches.

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References:

• EUVD Entry
• CVE-2023-38965
• Packet Storm Exploit
• GDPR Text