Microsoft Security Advisory reveals a vulnerability in Windows Phone OS that could allow information disclosure

Wireless PEAP-MS-CHAPv2 Authentication used by Windows Phone to access to wireless network.

According the Microsoft Security Advisory (2876146) a hacker exploiting the vulnerability in Windows Phone OS could access to victims encrypted domain credentials that could be used to collect sensitive data from corporate networks.

“To exploit this issue, an attacker controlled system could pose as a known WI-Fi access point, causing the targeted device to automatically attempt to authenticate with the access point, and in turn allowing the attacker to intercept the victim’s encrypted domain credentials. An attacker could then exploit cryptographic weaknesses in the PEAP-MS-CHAPv2 protocol to obtain the victim’s domain credentials. Those credentials could then be re-used to authenticate the attacker to network resources, and the attacker could take any action that the user could take on that network resource.” stated the bulletin.

The flaw is related to the WiFi authentication scheme (PEAP-MS-CHAPv2) implemented in Windows Phones for the access to wireless networks that are secured through WI-Fi Protected Access protocol version 2. The affected phone OSs are Windows Phone 8 and Windows Phone 7.8, Microsoft experts recommend to apply the suggested action to require a certificate verifying a wireless access point before starting an authentication process.