SQL injection vulnerability in authent.php4 in Nicolas Fischer (aka NFec) RechnungsZentrale V2 1.1.3, and possibly earlier versions, allows remote attackers to execute arbitrary SQL commands via the User field.
https://www.exploit-db.com/exploits/1699
https://exchange.xforce.ibmcloud.com/vulnerabilities/25911
http://www.vupen.com/english/advisories/2006/1425
http://secunia.com/advisories/19728
http://archives.neohapsis.com/archives/bugtraq/2006-04/0384.html