4 ms·

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 fil

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 :)