CVE-2024-42557

Executive Summary

CVE-2024-42557 is a Cross-Site Request Forgery (CSRF) vulnerability in the admin_modify_room.php component of an unnamed Hotel Management System, identified in commit 91caab8. An attacker can abuse this flaw to escalate privileges by tricking an authenticated administrator into submitting a crafted request that modifies room data, potentially leading to full administrative compromise. The vulnerability affects any deployment of this Hotel Management System running commit 91caab8 or subsequent commits that have not applied the unconfirmed patch; at this time, no public exploit code exists, yet the attack surface is internet-facing via the admin panel.

Technical Analysis

The vulnerability resides in admin_modify_room.php, a PHP script responsible for updating room records (e.g., name, type, price, availability) in the Hotel Management System. The flaw is a classic CSRF: the script performs state-changing operations (SQL UPDATE queries against the room table) without validating the origin of the HTTP request. Specifically:

• Missing CSRF token: The form rendered by admin_modify_room.php does not embed a per-session CSRF token (e.g., a hidden csrf_token field or SameSite cookie attribute).
• No Origin/Referer validation: The server does not check the Origin or Referer headers of POST/POST-submitted GET requests to ensure they originate from the same origin.
• Session-based authentication only: The admin session is tracked via cookies; the browser automatically attaches these cookies to any request, regardless of the requesting page’s origin.
• State-changing endpoint: The script accepts parameters such as room_id, room_name, room_type, price, and status, and directly updates the database without re-authentication or confirmation.

An attacker crafts a malicious HTML page (hosted on any domain) containing an auto-submitting form or an <img> tag pointing to http://victim-hotel/admin_modify_room.php?room_id=X&price=0&status=available. When a logged-in admin visits the attacker’s page, the browser sends the request with the admin’s session cookie, and the server processes it as a legitimate update. The CSRF vector can also be weaponized for privilege escalation: by modifying the room assignment fields or injecting content into fields that are later rendered without sanitization (e.g., room description), the attacker can plant stored XSS payloads that execute in other admins’ browsers, harvesting credentials or performing further admin actions (e.g., creating new admin users via other vulnerable endpoints).

Attack surface: The admin panel (/admin/ directory) is intended for internal use but is frequently exposed on the public internet without IP restrictions. The vulnerability is triggered only when an authenticated admin interacts with a malicious external page—no prior access to the victim network is required, making it a client-side attack vector that pairs well with spear-phishing.

Exploitation Scenarios

Scenario 1 — Direct Room Manipulation for Financial Fraud

1. Recon: Attacker identifies a target Hotel Management System via Shodan (e.g., http.title:"Hotel Management System") or via a Google dork targeting admin_modify_room.php. They enumerate room IDs by observing booking URLs or predictable IDs (e.g., room_id=1,2,3...).
2. Weaponization: Attacker hosts exploit.html on their server. The page contains:

   <form action="http://victim/admin/admin_modify_room.php" method="POST">
     <input name="room_id" value="1">
     <input name="price" value="0.01">
     <input name="status" value="booked">
     <input type="submit">
   </form>
   <script>document.forms[0].submit();</script>
   

3. Trigger: Attacker sends the victim admin a phishing email with a link to exploit.html (e.g., masked as an invoice). When the admin clicks, the form auto-submits. The browser includes the admin’s session cookie.
4. Impact: The server updates room 1’s price to $0.01 and marks it booked. The attacker then books that room at the manipulated price, causing direct financial loss and database integrity corruption.

Scenario 2 — Privilege Escalation via Stored XSS Chain

1. Recon: Same as above, but attacker focuses on the room_name or description textarea field.
2. Weaponization: The malicious form includes a payload:

   <input name="room_name" value='<script>fetch("/admin/admin_create_user.php",{method:"POST",body:"username=hacker&password=P@ss&role=admin"})</script>'>
   

3. Trigger: After the victim admin submits, the room name field is stored with the XSS payload. When any admin views the room management page, the script executes in their session.
4. Impact: The injected JavaScript issues a POST request to admin_create_user.php (another vulnerable endpoint) creating a new admin account. The attacker logs in as an admin, gaining full control of the hotel booking system, guest PII, and payment records.

Scenario 3 — Denial of Service via Mass Data Deletion

1. The attacker crafts a form that iteratively submits admin_modify_room.php with status=deleted for all room IDs from 1 to 200.
2. The admin visits the page; the browser fires 200 requests, each with the session cookie, wiping out the entire room inventory.
3. The hotel cannot take bookings until manual recovery, causing operational disruption and reputational damage.

Impact Assessment

Business Impact:

• Financial loss — price manipulation enables fraudulent bookings; guest booking data corruption can halt revenue.
• Reputation damage — publicized breach of a hospitality management system erodes customer trust; the system often holds guest PII (names, IDs, credit card data).
• Operational disruption — room inventory tampering leads to overbooking or no-availability, disrupting daily operations.

Affected Systems:
Any internet-accessible deployment of this Hotel Management System at commit 91caab8. No version range is known; the CVE description ties the flaw to a specific Git commit, implying the vendor maintains the code in a repository (likely GitHub), but the official project name is unconfirmed.

Blast Radius (using the CVSS subscores):
The vector AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H yields a High severity (7.0–8.9 band) despite the NVD listing "N/A" for the official score — the High rating is derived from:

• Confidentiality Impact: High — stored XSS can exfiltrate admin session cookies or guest data.
• Integrity Impact: High — arbitrary room data modification, including privilege escalation via XSS chain.
• Availability Impact: High — data deletion leads to denial of service.
• User Interaction: Required — the admin must click a malicious link; this is a single-click phishing scenario, reducing exploitation complexity but still requiring social engineering.

Blast Radius Scope: Unchanged (U) — the CSRF cannot directly pivot to other servers, but the XSS chain can pivot within the application to full admin takeover.

Detection Guidance

Sigma Rule

title: CSRF Exploitation Attempt Against Hotel Admin Room Modify Endpoint
id: 3f8a2b9e-4c31-4f7a-bd11-4f5d7a2c9e21
status: experimental
description: Detects requests to admin_modify_room.php with a non-standard Referer or Origin header, indicating potential CSRF.
logsource:
  category: webserver
  product: apache
  service: access
detection:
  selection:
    cs-method:
      - POST
      - GET
    c-uri|contains: admin_modify_room.php
    c-referer|contains|all:
      - -example.com
      - -victimhotel.com
  condition: selection
  timeframe: 5m
fields:
  - src_ip
  - c-uri
  - c-referer
falsepositives:
  - Bookmark links from external content management systems
  - Legitimate integrations from partner booking sites
level: high

YARA Rule

rule CVE_2024_42557_CSRF_Exploit_Form
{
    meta:
        author = "ValterSec TI"
        description = "Detects malicious HTML forms targeting admin_modify_room.php for CSRF"
        cve = "CVE-2024-42557"
        date = "2025-01-01"
    strings:
        $form_action = /<\s*form[^>]+action\s*=\s*["'][^"']*admin_modify_room\.php["']/i
        $field_room = /<\s*input[^>]+name\s*=\s*["'](?:room_id|room_name|room_type|price|status)["']/i
        $auto_submit = /<\s*script[^>]*>\s*(?:document\.forms\[[0-9]+\]\.submit\(\)|window\.onload\s*=\s*function\s*\(\)\s*\{[^}]*submit\s*\(\))/i
        $hidden_post = /type\s*=\s*["']hidden["']/i
    condition:
        #form_action >= 1 and #field_room >= 3 and ($auto_submit or $hidden_post)
}

Suricata IDS Rule

alert http any any -> any any (msg:"CVE-2024-42557 CSRF Attempt on Hotel admin_modify_room";
    flow:to_server,established;
    content:"admin_modify_room.php"; http_uri; nocase;
    content:"room_id"; http_client_body; nocase;
    content:"price"; http_client_body; nocase;
    pcre:"/Referer:\s*(?!https?:\/\/victim\.com)/i";
    reference:cve,2024-42557;
    classtype:attempted-admin;
    sid:2024701; rev:1;)

Note: The rule triggers on HTTP traffic containing the vulnerable URI, POST body parameters, and a Referer that does not match the legitimate site (victim.com). Adjust the allowed Referer domain accordingly.

Elastic Detection

sequence by source.ip with maxspan=5m
  [network where destination.port == 80 or destination.port == 443
   and http.request.method in ("POST", "GET")
   and http.request.uri contains "admin_modify_room.php"
   and not http.request.referrer starts with "http://victim.com"
   and not http.request.referrer starts with "https://victim.com"]
  [http where http.response.status_code == 200 and http.request.body contains "room_id"]

Splunk SPL Query

index=web sourcetype=access_combined
| eval uri = lower(uri_path)
| where uri LIKE "%admin_modify_room.php%"
| eval is_external = if (match(referer, "(?i)^https?://(?!victim\.com)"), "true", "false")
| where is_external == "true"
| stats count by clientip, uri, referer, method
| where count > 1
| sort - count

Wazuh OSSEC Rule

<group name="csrf,">
  <rule id="100425" level="8">
    <if_sid>31100</if_sid>
    <match>admin_modify_room\.php</match>
    <description>CVE-2024-42557: Potential CSRF request to admin_modify_room.php detected</description>
    <field name="referer">\.(?!victim\.com)</field>
    <group>web_application_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 (apply within 24–48 hours):

   • Restrict access to the /admin/ directory via firewall rules to only trusted IPs or a VPN — this reduces the exposure of admin_modify_room.php to internal users only, making CSRF exploitation require a prior foothold.
   • Implement a Web Application Firewall (WAF) rule to block requests to admin_modify_room.php that lack a matching Origin or Referer header.
   • Enforce SameSite=Lax or SameSite=Strict on all session cookies by editing php.ini (session.cookie_samesite = Lax) to prevent cross-site cookie attachment in most modern browsers (Chrome, Firefox, Edge). This alone neutralizes the primary CSRF vector for all browsers adopting the standard.

2. Patch/Upgrade Steps:

   • The CVE description indicates the flaw is in commit 91caab8; the unconfirmed patch is claimed to exist in a later commit. Check the vendor’s Git repository for commits after 91caab8 that touch admin_modify_room.php. If a newer commit exists, upgrade to the latest revision.
   • If the source is not accessible or the patch is not independently verifiable, do not trust the claim blindly — audit the code yourself: verify that a CSRF token is generated, stored in the session, and validated on POST.
   • As a permanent fix, add CSRF token generation/validation to admin_modify_room.php and all other admin endpoints (e.g., using PHP’s hash_hmac with a session secret).

3. Long-Term Hardening:

   • Implement Origin header validation server-side as defense-in-depth, even after CSRF tokens are added; never rely solely on Referer (which can be stripped by privacy settings).
   • Run a static code analysis tool (e.g., PHPStan, RIPS) over the entire PHP codebase to identify other missing CSRF protections.
   • Require re-authentication (e.g., password prompt) for any privilege-escalating action such as user creation, not just room modification.
   • Segment the admin panel onto a separate internal network with no direct internet exposure; consider placing it behind a reverse proxy with mandatory SSO.

References

1. NVD Entry: https://nvd.nist.gov/vuln/detail/CVE-2024-42557 — Official CVE record (description, no supported CVSS vector).
2. Git Commit Reference: The vulnerable commit 91caab8 is referenced in the CVE description; the exact repository URL is unconfirmed—likely a GitHub repo for an opensource Hotel Management System.
3. MITRE ATT&CK: https://attack.mitre.org/techniques/T1190/ — T1190 Exploit Public-Facing Application (tactic: Initial Access).
4. CWE-352 Reference: https://cwe.mitre.org/data/definitions/352.html — Cross-Site Request Forgery weakness description and mitigation patterns.

Threat Actor Campaigns / ITW Evidence: No known active campaigns exploiting CVE-2024-42557 have been reported as of this writing. The vulnerability is not listed in CISA’s Known Exploited Vulnerabilities (KEV) catalog, and no public exploit code (Metasploit, Exploit-DB, or GitHub PoC) has been identified. However, given the commonality of CSRF in PHP CRUD applications and the ease of crafting exploit forms, proactive detection and patching are strongly recommended.