Critical · published June 5, 2019
🚨 A casual mishap with RAR filenames could grant attackers full control! This CVE-2019-12739 in Nextcloud's Extract add-on before version 1.2.0 enables Remote Code Execution just by slipping in shell metacharacters. 🔥 Think of it as a restaurant accepting any order written on a napkin without checking the ingredients—one sneaky order could lead to a chaos in the kitchen! In this case, the RAR filename is the napkin, and the server is the unsuspecting chef. An attacker could exploit this vulnerability to run any code they wish on your server, potentially leading to data breaches or full system takeover. Imagine a burglar walking through the front door because the restaurant forgot to check the ID of a customer! This could be absolutely devastating for your data security.
Think of it as a restaurant accepting any order written on a napkin without checking the ingredients—one sneaky order could lead to a chaos in the kitchen! In this case, the RAR filename is the napkin, and the server is the unsuspecting chef. This vulnerability arises from insufficient validation of RAR filenames in the ajax/extractRar.php file, allowing shell metacharacters to be executed as code. Simply put, it's like a server that trusts any command thrown its way without asking for ID or permission.
An attacker could exploit this vulnerability to run any code they wish on your server, potentially leading to data breaches or full system takeover. Imagine a burglar walking through the front door because the restaurant forgot to check the ID of a customer! This could be absolutely devastating for your data security. Update your Nextcloud Extract add-on to version 1.2.0 or higher immediately to close this door to attackers. Additionally, consider implementing strict filename validation and user permissions to bolster security further. You've got this! By following these steps, you’ll regain control and keep your Nextcloud secure! 🛡️