Showing 44 Result(s)

Writeup: Web shell upload via obfuscated file extension

Lab link. If the application has taken precautions for the file extension, there are several ways to bypass this precaution. In this lab, we use the null byte method to bypass the file extension blocking. In Requesat’s response, we see that our file was uploaded correctly. In the GET /files/avatars/ we correct our file name …

Writeup: Web shell upload via extension blacklist bypass

Lab link. The application has used a blacklist for security, but if we upload the .htaccess file, we can allow any file extension we want on the server. The file with the .php extension does not work. We make changes to the POST /my-account/avatar request. Now we can upload files with .l33t extension. We change …

Writeup: Web shell upload via path traversal

Lab link. In some systems, there may be more than one vulnerability, or we may continue with a different vulnerability in the continuation of one vulnerability. In this lab, we can upload files thanks to path traversal. In the lab, we are asked to access the file /home/carlos/secret. We create a php file to access …

Writeup: Blind SSRF with out-of-band detection

Lab link. Blind SSRF occurs when an application can be encouraged to send a back-end HTTP request to a given URL, but the response from the back-end request is not returned in the application’s front-end response. Using Burp Collaborator we can create unique domains and send them as payloads to the application. We can monitor …

Writeup: SSRF with whitelist-based input filter

Lab link. Another SSRF measure is Whitelist-Based. The application only allows entries that match a whitelist. The filter can search for a match inside the input. We bypass this filter by exploiting inconsistencies in URL parsing. We try to find an SSRF vulnerability in the check stock feature in the application. We try some SSRF …

Writeup: SSRF with blacklist-based input filter

Lab link. Blacklist-based management can be used as a precaution against SSRF attacks. Some applications can block IP and keywords such as localhost, admin, or 127[.]0[.]0[.]0[.]1. This method can be bypassed. We navigate the application and find where an HTTP request communicates with the API endpoint. This is the stock check section. With the stockApi …

Writeup: Stealing OAuth access tokens via a proxy page

Lab link. First, we check if redirect_uri has a defense against path traversal. Browse other pages. Requests are followed in the comments section of the blog page. window.location.href and postMessage() are used in the comment section. window.location.href contains the current URL of the browser. postMessage() function is used in WebExtension API to communicate messages between …