SilverStripe CMS 3.6.2 – CSV Excel Macro Injection
Exploit Title: SilverStripe CMS - 3.6.2 CSV Excel Macro Injection Vendor Homepage: https://www.silverstripe.org/ Software Link: https://www.silverstripe.org/download Discovered by: Ishaq Mohammed Contact: https://twitter.com/security_prince Website: https://about.me/security-prince Category: web apps Platform: PHP Description: In the CSV export feature of the SilverStripe CMS, it's possible for the output to contain macros and scripts, which if imported without sanitization into software (including Microsoft Excel) may be executed. Proof of Concept Steps to Reproduce: 1. Login with normal user's credentials 2. Access the below URL via your browser: http://localhost/SilverStripe/admin/myprofile 3. Enter the below payload in the "First Name" field and save the profile" @SUM(1+1)*cmd|' /C calc'!A0 4. Log in with admin's credentials on a different browser 5. Access te security page at the below link: http://localhost/SilverStripe/admin/security/ 6. Click on "Export to CSV" option and open the exported CSV file in any Spreadsheet application Solution: The issue has been fixed in the latest release of SilverStripe which can be downloaded from here: https://www.silverstripe.org/download Reference: https://www.silverstripe.org/download/security-releases/ss-2017-007 |