CVE-2024-42559

Executive Summary

CVE-2024-42559 is an authentication bypass vulnerability in the login component (process_login.php) of an unidentified Hotel Management System application, specifically in commit 79d688. An attacker can authenticate to the application without supplying a valid password, effectively bypassing the entire authentication mechanism. This affects any deployment of this Hotel Management System built from the vulnerable commit. The impact is critical: an unauthenticated remote attacker gains full administrative access to the hotel management platform, enabling data theft, service disruption, and lateral movement into backend networks if the application is internet-exposed.

Technical Analysis

The vulnerability resides in process_login.php, the server-side script responsible for validating user credentials during the login flow. The flaw is a classic authentication logic error: the script fails to correctly verify that a submitted password matches the stored hash for the provided username.

Vulnerability Mechanism: The PHP logic likely performs a query such as SELECT * FROM users WHERE username = '$_POST[username]' and then checks only whether a row was returned, omitting or incorrectly implementing the password_verify() or equivalent comparison. In such cases, submitting a valid username (e.g., admin) with an empty or arbitrary password field causes the script to treat the successful database row retrieval as successful authentication. The commit hash 79d688 indicates the state of the codebase where this defect was introduced, and no upstream fix has been independently confirmed (patch confidence: 2/4 — single source claim only).

Attack Surface: This is a pre-authentication flaw. The login page is the only component required for exploitation. If the Hotel Management System is exposed on the internet or an untrusted network segment (common for property management dashboards), the attack surface is fully remote. The application likely runs on a typical LAMP stack (Linux, Apache, MySQL, PHP) given the .php extension. The process_login.php script is invoked via HTTP POST requests to the login endpoint.

Code-Level Context: While the exact source is not publicly disclosed, the vulnerability class is consistent with CWE-287: Improper Authentication — the application fails to enforce a required authentication step (password validation). The absence of a CVSS vector and score (N/A) means the maintainer or CNA has not submitted an assessment; however, based on the vulnerability class, the severity would align with the Critical range (9.0-10.0) due to trivial remote exploitation and full system compromise potential.

Exploitation Scenarios

Even without a public PoC, the exploitation chain is straightforward. An attacker performs the following steps:

1. Reconnaissance / Target Identification:

   • Scan for exposed Hotel Management System login pages using Shodan dorks such as http.title:"Hotel Management System" or http.component:"PHP" http.title:"Login" combined with hotel-specific keywords.
   • Identify the login endpoint — typically /login.php or /index.php — and confirm the server responds with a PHP-based login form.

2. Trigger / Weaponization:

   • Craft an HTTP POST request to process_login.php with parameters username=admin (or any valid username enumerated via predictable defaults like admin, manager, reception) and password=anything or an empty value.
   • Example request:

     POST /process_login.php HTTP/1.1
     Host: target
     Content-Type: application/x-www-form-urlencoded
     
     username=admin&password=invalid
     

   • If the username is valid, the faulty logic grants a session. Optionally, use an SQL injection payload in the username field (e.g., ' OR '1'='1' -- ) if the underlying query is also injectable, but this is a secondary vector.

3. Payload / Execution:

   • After successful authentication, the application issues a Set-Cookie header with a session token. The attacker uses this cookie to access authenticated functions, including reservation management, guest records, billing, and possibly administrative panels (user creation, room rate configuration).
   • If the application allows file uploads (common in hotel systems for guest documents), the attacker may upload a PHP web shell and achieve remote code execution with the web server's privileges (www-data on Linux).

4. Post-Exploitation Impact:

   • Exfiltrate guest PII (names, ID/passport numbers, credit card data if stored), internal staff credentials, and financial records.
   • Modify reservations, lock out legitimate staff by changing admin passwords, or encrypt the database with ransomware.
   • Use the compromised server as a pivot point to scan the internal hotel network (CCTV systems, property management servers, IoT door-lock controllers).
   • If the application is connected to payment gateways, the attacker may attempt transaction fraud or card skimming through API credential theft.

Impact Assessment

• Confidentiality: Complete loss — unauthorized access to guest PII, financial data, and internal staff records. CVSS confidentiality impact would score HIGH if a vector were assigned.
• Integrity: High — attackers can modify reservations, alter room rates, create rogue admin accounts, or deface the portal.
• Availability: High — the attacker can lock out legitimate users, delete database records, or deploy ransomware.
• Affected Systems: Any deployment of this Hotel Management System built from commit 79d688. Given the commit-pinned nature, the affected version range is effectively "all versions up to and including commit 79d688" — no formal version numbers are published.
• Blast Radius: The web application itself, the underlying database server (MySQL), and any connected backend services (email, payment APIs, external booking engines). If the PHP process runs with elevated privileges or misconfigured sudoers, host OS compromise is possible.
• Business Impact: For a hotel, this translates to regulatory fines (GDPR/CCPA for PII breaches), PCI-DSS non-compliance penalties, reputational damage, and operational downtime. Legal liability from guests whose data is exposed compounds the financial loss.

Detection Guidance

All detection rules target the authentication bypass pattern: anomalous POST requests to login processing scripts with minimal password content or predictable usernames, followed by rapid authenticated activity.

Sigma Rule

title: Hotel Management System Authentication Bypass Attempt (CVE-2024-42559)
id: 4c5a9e6f-7b21-4a3c-9d4e-8f1a2b3c4d5e
status: experimental
description: Detects HTTP POST requests to process_login.php with empty or single-character password parameters, indicating potential auth bypass.
logsource:
  category: webserver
  product: apache
detection:
  selection:
    cs-method: POST
    cs-uri-query|contains: process_login.php
    cs-uri-query|contains|all:
      - 'username='
      - 'password='
  filter_common:
    cs-uri-query|contains: 'password=mypassword'
  condition: selection and not filter_common
  # Expand filter with legitimate password length/heuristics in production
  timeframe: 5m
level: high
falsepositives:
  - Misconfigured test clients sending empty passwords
  - Legacy scripts
tags:
  - attack.t1190
  - cve.2024-42559

YARA Rule

rule CVE_2024_42559_AuthBypass_SourcePattern
{
    meta:
        author = "Valterit SOC"
        date = "2025-01-15"
        description = "Detects PHP source code pattern characteristic of missing password verification in hotel management login script."
        cve = "CVE-2024-42559"
    strings:
        $a = "process_login.php"
        $b = "username" nocase
        $c = "password" nocase
        $d = "mysqli_query" nocase
        $e = "num_rows > 0"
        $f = "session_start" nocase
    condition:
        all of them and (#e >= 1)
}

Suricata IDS Rule

alert http any any -> $HOME_NET any (msg:"CVE-2024-42559 Hotel Management Auth Bypass Attempt"; flow:established,to_server; http.method; content:"POST"; http.uri; content:"process_login.php"; http.client_body; pcre:"/username=[^&]+&password=[^&]{0,3}/i"; classtype:attempted-user; sid:202442559; rev:1;)

Elastic Detection

sequence by host.name, source.ip with maxspan=5m
  [ network where network.protocol == "http" and http.request.method == "POST" and
    url.path contains "process_login.php" and
    // Match username present, password empty or very short
    http.request.body.content : "username=*&password=*" and
    not http.request.body.content : "password=*[a-zA-Z0-9]{8,}*"
  ] 
  [ authentication where event.action == "user_login" and outcome == "success" and
    // Success immediately following suspicious POST = bypass
    user.name : "admin" 
  ]

Splunk SPL Query

index=web sourcetype=access_combined
| where method="POST" AND uri_path="*process_login.php*"
| rex field=form_data "password=(?<password_len>\w{0,8})"
| eval flag=if(len(password_len)<4 OR isnull(password_len), "suspicious", "normal")
| stats count by clientip, password_len, flag, uri_path
| where flag="suspicious"
| `ut_parse` clientip
| table _time, clientip, uri_path, password_len, count
| sort -count

Wazuh OSSEC Rule

<rule id="100425" level="12">
  <decoded_as>web-accesslog</decoded_as>
  <match>process_login.php</match>
  <regex>POST \S+ process_login\.php\S* 200</regex>
  <regex>password=.*&amp;|password=.* </regex>
  <description>CVE-2024-42559 - Hotel Management System authentication bypass attempt (suspicious POST to process_login.php)</description>
  <group>authentication_failures,pci_dss_6.5.10,gdpr_32,</group>
  <mitre>
    <id>T1190</id>
  </mitre>
  <options>no_full_log</options>
</rule>

Mitigation & Patch Guidance

Patch confidence: 2/4 (CLAIMED) — a single source claims a patch exists, but it has not been independently confirmed or published in an official advisory.

1. Immediate Mitigations:

   • Restrict network access: Place the Hotel Management System behind a VPN or internal network only. Deny internet-facing access via firewall rules or a reverse proxy with IP allowlisting.
   • Enable Multi-Factor Authentication (MFA) at the application layer if the code supports it; otherwise, wrap the login endpoint with a web application firewall (WAF) rule that blocks requests where the password parameter is empty or shorter than a configured minimum (e.g., 8 characters).
   • Temporary credential rotation: If feasible, disable the admin account and require staff to authenticate via a secondary SSO gateway until patched.

2. Patch/Upgrade Steps:

   • Obtain the patched source code from the vendor. Since the patch is "claimed" but not independently confirmed, contact the software provider directly and request the commit or version that addresses 79d688.
   • If the vendor is unresponsive, manually patch the vulnerable logic: open process_login.php and ensure the password comparison uses password_verify() against the stored hash, and verify the result before establishing a session. Rebuild the application from the patched source.
   • Deploy the updated build to a staging environment, rerun authentication tests, then promote to production.

3. Long-Term Hardening:

   • Adopt a secure-by-design framework: Replace the custom authentication with a hardened library (e.g., Laravel/PHP's built-in auth or OAuth2/OpenID Connect).
   • Enforce least privilege for database connections: Ensure the web app's MySQL user lacks FILE and GRANT privileges to limit post-exploitation impact.
   • Implement continuous vulnerability scanning for this CVE and similar auth flaws using tools like Nuclei (once a template exists) or OWASP ZAP.
   • Conduct regular source code audits with static analysis tools (e.g., PHPStan, Psalm) to catch authentication logic errors before deployment.

References

• NVD Entry: CVE-2024-42559 — Official record with description; CVSS and CWE pending.
• GitHub Commit Reference: 79d688 — Vulnerable commit of the Hotel Management System (repository not publicly identified; locate via vendor communication or code search).
• MITRE ATT&CK: T1190 — Exploit Public-Facing Application — Primary tactic for this vulnerability.
• CISA Known Exploited Vulnerabilities (KEV): CISA KEV Catalog — This CVE is NOT currently listed (confirmed), so no active exploitation data is available from CISA.
• OWASP: Authentication Cheat Sheet — Best practices for preventing this vulnerability class.

Threat Actor Activity: No known threat actor campaigns or exploit-in-the-wild evidence has been reported for this CVE as of the writing date. The EPSS score is not yet assigned by FIRST.org; monitor the EPSS feed for future scoring to prioritize remediation.