Questions and Answers

How do I collect points?

  • +5
    Chosen as best answer
  • +1
    Posted answer
  • +1
    Posted question
  • +1
    Thumb up
  • -1
    Thumb down

by FNNewGuy in Challenge Help about November 8, 2016 open - report

Quick question about basic 38 and basic 39

On the two challenges mentioned above, the attacker has to upload a malicious file through an uploader designed to allow gifs only. I've researched multiple ways of doing this but none have worked so far (it may be a problem with my understanding but I had an idea that I thought would work for sure). On to the question, is it possible to use alternate data streams to fool the uploader into accepting a php file attached to the gif? I've tested python with an alternate data stream file (nothing in file,everything in stream) and the script ran. But the uploader only picks up the gif. ***is this server on the ntfs file system or is it ext4? 

Answer: 1 • Score 0 • Views: 383
Browse by
  • 116

    by Nightraven about December 9, 2016

    Filesystem is irrelevant for the mission. You need to execute a PHP script from a GIF file, or make it believe that a PHP file is a GIF file. One or the other, I don't remember.

    • Score: 0
You must login to post an answer.