4 ms·

Or, if you're really clever - and Ange Albertini is quite good at this kind of trick - you can design the PDF so that the different garbage in the middle cause

by makomk 10y ago

Or, if you're really clever - and Ange Albertini is quite good at this kind of trick - you can design the PDF so that the different garbage in the middle causes the other, unchanged content to be interpreted differently in the two PDF files, possibly even designing it so that the intended contents of each PDF is treated as garbage and ignored entirely in the other PDF.

stcredzero 10y ago
With many image formats, you can just concatenate whatever you want at the end of the file, and the OS and programs will obliviously read and copy the whole file, while the image libraries will happily ignore the extra data.
- cestith 10y ago
  And then you put PHP tags in that content at the end, and change the .htaccess file to process *.jpeg as PHP scripts, and your webshell looks benign until someone has that in mind looking through the account.
  - dogma1138 10y ago
    You don't need to find a collision to do that :)