NXP Semiconductors MIFARE Classic Smartcard - Multiple Security Weaknesses

                                                source: http://www.securityfocus.com/bid/31853/info

MIFARE Classic is prone to multiple security weaknesses:

1. A security weakness may allow attackers to recover the internal state of the linear feedback shift register.

2. A security weakness may allow attackers to recover the previous state of the linear feedback shift register.

3. A security weakness may allow attackers to invert the filter function and potentially gain access to the private key.

4. A security weakness may allow attackers to reduce the search space for tag nonces.

Exploiting these issues in combination may allow attackers to gain access to the smartcard's secret key. Successful exploits will allow attackers with physical access to an RFID reader to bypass certain physical security restrictions. 

http://www.exploit-db.com/sploits/32501.tgz