WordPress Large File Upload Error XSS

Uploaded files present a huge risk in the server. The uploaded files can be malicious and can cause damage to the server with the sensitive data breach. It could also give complete access to the attacker. When an attacker wants to attack a web application. He will try different methods to upload his malicious file. After a successful upload, he will find different ways to execute the file. A successful execution will give what the attacker wants.

Many servers are vulnerable to cross-site scripting vulnerability during upload of very large files. This vulnerability is faced due to the error message, it is not properly restricted. In WordPress versions before 4.7.5, cross-site scripting (XSS) vulnerability existed while attempting to upload huge files. This vulnerability existed because the error message did not correctly restrict the presentation of the filename.

Impact and Fixes

Written by

Sooraj V Nair

Cyber Security Engineer

Sooraj was probably the kid who opened up a remote control just to see what was inside, then had to figure out how to put it back together before anyone noticed. That curiosity eventually found its way into cybersecurity, where breaking things is actually part of the job description. Today, he explores vulnerabilities, analysis threats, and helps build safer digital spaces. His favourite question remains the same: “What happens if I try this?”