A security flaw in WPA2, the security protocol for most modern WiFi systems, could allow an attacker to steal sensitive data including emails, credit card numbers and passwords, Researchers at Belgian university KU Leuven reported Monday. Depending on the network configuration, the flaw also could allow an attacker to inject or manipulate information in the system -- for example, inject ransomware or other malware into websites being used. The weakness is in the WiFi standard itself, not in any particular products or implementations.