Unmasking Open Redirect Vulnerabilities: A Real-World Discovery

While testing a web application, I discovered an Open Redirect vulnerability that could potentially be used for phishing or redirecting unsuspecting users to malicious websites. Here’s a quick breakdown of the steps I followed to exploit it.

The Vulnerable URL

I came across this URL during my testing:

https://example.com/actions.php?action="enter_site_here"

It seemed like the action parameter was used to define where the page should redirect users. Naturally, I decided to test if I could manipulate it.

Step-by-Step Exploitation

Analyze the URL:
I noticed that the action parameter could potentially accept a custom URL.Craft a Malicious URL:
I replaced the placeholder value with my test URL:https://example.com/actions.php?action=http://evil.compoc : 1Observe the Redirect:
The application redirected me directly to http://evil.com. No validation or warnings were in place to block the redirect.poc 2

With this knowledge, attackers could craft phishing links that look legitimate but secretly redirect users to malicious websites.

Thank you for taking the time to read this! Stay curious, stay secure.