Showing posts with label PHP. Show all posts
Showing posts with label PHP. Show all posts

Thursday, 19 January 2012

LFI attacks for Predators

What is an LFI vulnerability??
what? you don't know!!? lulz, an LFI or (Local file inclusion)  vulnerability ---much like other web attacks, exists when unclean user input is used to determine input to any of the  follow php functions 
  • include : "Files are included based on the file path given or, if none is given, the include_path specified. If the file isn't found in the include_path, include() will finally check in the calling script's own directory and the current working directory before failing. The include() construct will emit a warning if it cannot find a file; this is different behavior from require(), which will emit a fatal_error."
an interesting thing to note is that include will actually search for files with the specified name if an absolute path is not given the script will search for it in the include_path, this means if you can influence the environment variables that a script runs under, you may be able to fool it into including the wrong files!
  • readfile:"Reads a file into the output buffer"
  • include_once: "The include_once() statement includes and evaluates the specified file during the execution of the script. This is a behavior similar to the include() statement, with the only difference being that if the code from a file has already been included, it will not be included again. As the name suggests, it will be included just once"
(There may be other functions that allow LFI attacks, if so i forgot lols)

Okay all of these functions have one thing in common, they allow PHP scripts to read/display content of specified files, the hack comes in when this specification is unchecked. You could for example fool a script into reading the password file

Me performing an LFI attack

As I've done here, (hehehe i wish i could tell you who's server this was!!).

Now this part of the tutorial you expect me to demonstrate an LFI, right?? Wrong!! I actually care about whether this information is useful to you!! So I'm gonna show how to find servers with LFI vulnerabilities