IT administrators are being advised to upgrade to BlackBerry Device Software 4.2 Service Pack 1 to fix a flaw in earlier versions attackers could exploit to cause a denial of service.
According to the French Security Incident Response Team (FrSIRT), the problem is an error in the BlackBerry browser that fails to properly handle overly long URLs. Attackers could exploit this to cause a vulnerable device to become slow or to stop responding by tricking a user into following a specially crafted link.
The problem affects BlackBerry Device Software version 4.2 and prior. The solution is to upgrade to BlackBerry Device Software 4.2 Service Pack 1.