CVE-2025-24663

Executive Summary

CVE-2025-24663 is a critical Blind SQL Injection vulnerability affecting the WordPress plugin Simple Download Monitor by mra13, up to and including version 3.9.25. The vulnerability arises from improper neutralization of special elements used in an SQL command, allowing an unauthenticated attacker to perform blind SQL injection attacks. This can lead to unauthorized access to sensitive data, including user credentials and database contents. The CVSS score of 7.6 (High) reflects the ease of exploitation and potential for significant data compromise. No public proof-of-concept (PoC) or patch is currently available, increasing the urgency for defensive measures.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed via the official WordPress plugin repository. Users are advised to monitor for updates from the vendor and consider disabling the plugin until a patch is released. The lack of OSV or GitHub advisory data indicates limited public disclosure, but the risk remains high due to the plugin's widespread use.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L
• Base Score: 7.6 (High)
• Attack Vector: Network (AV:N) – Exploitable remotely.
• Attack Complexity: Low (AC:L) – No special conditions required.
• Privileges Required: None (PR:N) – No authentication needed.
• User Interaction: None (UI:N) – No user action required.
• Scope: Unchanged (S:U) – Vulnerability affects only the vulnerable component.
• Confidentiality Impact: High (C:H) – Full database read access possible.
• Integrity Impact: Low (I:L) – Limited data modification possible.
• Availability Impact: Low (A:L) – Potential for denial of service via SQL injection.

Threat Level: High. The vulnerability is remotely exploitable without authentication, and blind SQL injection techniques can extract sensitive data over time.

Deep Dive & Mechanics

The vulnerability exists in the simple-download-monitor plugin's handling of user-supplied input within SQL queries. The plugin fails to properly sanitize or parameterize input used in database operations, allowing an attacker to inject arbitrary SQL commands. Blind SQL injection means the attacker does not receive direct error messages but can infer information based on the application's response (e.g., timing delays or boolean responses).

Attack Vector:

• The attacker sends crafted HTTP requests to endpoints that process download monitoring data.
• The injected SQL payload is executed against the WordPress database.
• Using blind techniques (e.g., AND 1=1 vs AND 1=2), the attacker can enumerate database tables, columns, and values.

Potential Impact:

• Extraction of WordPress user credentials (hashed passwords).
• Access to sensitive plugin data (download logs, user metadata).
• Potential privilege escalation if admin credentials are compromised.

Vulnerable vs. Patched Code

Since no patch is available, a comparison cannot be made. However, the vulnerable code likely uses string concatenation for SQL queries, such as:

$sql = "SELECT * FROM {$wpdb->prefix}downloads WHERE id = " . $_GET['download_id'];

A patched version would use prepared statements:

$sql = $wpdb->prepare("SELECT * FROM {$wpdb->prefix}downloads WHERE id = %d", $_GET['download_id']);

Exploitation & Lab Setup

Red Team (Offensive)

Lab Setup:

1. Install WordPress with Simple Download Monitor plugin version 3.9.25.
2. Ensure the plugin is active and accessible via a web server.

Exploitation Steps:

1. Identify vulnerable parameters (e.g., download_id, log_id).
2. Use a tool like sqlmap to automate blind SQL injection:

   sqlmap -u "http://target/wp-admin/admin-ajax.php?action=sdmonitor_log&download_id=1" --batch --dbs
   

3. Manually test with boolean-based payloads:

   GET /wp-admin/admin-ajax.php?action=sdmonitor_log&download_id=1 AND 1=1 HTTP/1.1
   Host: target
   

   Compare responses to infer true/false conditions.

Note: No public exploit code is available; the above is a generic approach.

Blue Team (Defensive)

Detection:

• Monitor for unusual SQL error messages or time delays in responses.
• Look for patterns like AND, OR, UNION, SLEEP() in request parameters.
• Use WAF rules to block SQL injection patterns.

Mitigation:

• Disable the plugin until a patch is released.
• Implement input validation and parameterized queries.
• Apply virtual patching via WAF.

Indicators of Compromise (IOCs)

• Network IOCs:
  • HTTP requests containing SQL keywords in parameters (e.g., download_id=1 AND 1=1).
  • Unusual response times (e.g., SLEEP(5) causing delays).
• File IOCs:
  • Modified plugin files (e.g., simple-download-monitor.php).
  • Suspicious entries in WordPress debug logs.
• Database IOCs:
  • Unexpected queries in MySQL slow query log.
  • New or modified database users.

Detection Engineering

YARA Rule

rule CVE_2025_24663_Blind_SQLi {
    meta:
        description = "Detects blind SQL injection attempts against Simple Download Monitor"
        author = "Valters IT"
        date = "2025-04-10"
        cve = "CVE-2025-24663"
    strings:
        $sqli1 = /download_id=[0-9]+.*AND.*[0-9]+=[0-9]+/ nocase
        $sqli2 = /download_id=[0-9]+.*OR.*[0-9]+=[0-9]+/ nocase
        $sqli3 = /download_id=[0-9]+.*SLEEP\(/ nocase
    condition:
        any of them
}

Sigma Rule

title: Blind SQL Injection Attempt Against Simple Download Monitor
id: 8f4a2b1c-3d5e-4f7a-9b8c-1d2e3f4a5b6c
status: experimental
description: Detects SQL injection patterns in HTTP requests targeting Simple Download Monitor plugin
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        c-uri|contains: '/wp-admin/admin-ajax.php'
        c-uri|contains: 'action=sdmonitor_log'
        cs-uri-query|contains: 
            - 'AND'
            - 'OR'
            - 'SLEEP('
            - 'UNION'
    condition: selection
falsepositives:
    - Legitimate use of 'AND' in parameter values (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-24663 Blind SQL Injection Attempt"; flow:to_server,established; content:"/wp-admin/admin-ajax.php"; http_uri; content:"action=sdmonitor_log"; http_uri; pcre:"/(AND|OR|SLEEP\()/i"; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin if not critical to operations.
2. Apply virtual patching via WAF to block SQL injection patterns.
3. Monitor logs for exploitation attempts.

Long-term Fix:

• Await an official patch from the vendor (mra13).
• If no patch is released, consider replacing the plugin with an alternative.

Best Practices:

• Always use parameterized queries in WordPress plugin development.
• Regularly update plugins and core.
• Implement a Web Application Firewall (WAF).

Valters IT signature: This report is provided for educational and defensive purposes only. Unauthorized exploitation of this vulnerability is illegal.