Piti's blog is a very vulnerable web app written to illustrate a php security training
The app is at least vulnerable to 
SQL INJECTION
XSS
Code and instruction injection
Cross site request forgery
Copyright (C) 2012 Manuel Silvoso

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.