skip to content

poster-thief-1

vikvanderlinden 1 min read

Look at this new site, it’s very secure and has good security policies!

This challenge hints to the security policies on the website.

On the site, the following message is displayed in the upper right corner of the site: “Please contact me if you find any security problems in this amazing story!”

These two messages hint to a very specific file: security.txt. This file is defined as a standard: RFC9116. Basically: This is a file that allows you to communicate contact information that users should reach out to if they have found some sort of security vulnerability or problem.

Solving this challenge is a matter of visiting that file and reading the flag. The challenge boils down to understanding that the descriptions point to the security.txt file and finding the location of that file. When found (it is located in the .well-known directory), upon a simple visit you can see that the flag is simply written in the security.txt-file.

At the path /.well-known/security.txt, you’ll find:

1Contact: mailto:security@stellarvector.be
2# So secure!!
3# sv{s3cur1ty.txt_ftw!}

For more information regarding the security.txt usage, read: https://almanac.httparchive.org/en/2022/security#securitytxt

Go ahead and visit some other websites’ security.txt policies:

about the author

vikvanderlinden

Stellar Vector team lead. Specializes in web and network security.

more like this

web

poster-thief-2

Detailed exploration of Path Traversal vulnerabilities. Explains how to bypass non-recursive traversal filters by nesting sequences to reach sensitive system files.

by vikvanderlinden 5 min
web

poster-thief-3

Hands-on tutorial on manipulating HTTP headers using curl. Demonstrates how to bypass server-side checks for User-Agent, Referer, and custom headers.

by vikvanderlinden 3 min