Microsoft has warned IT departments to batten down their Wi-Fi networks following the discovery of a security vulnerability in Windows Phones that leaks users' passwords.
Miscreants who set up rogue hotspots can grab from devices employees' encrypted domain credentials, needed to authenticate with corporate systems and access network resources. But the algorithm encrypting this sensitive data is cryptographically weak, allowing hackers to recover the login details and use them to masquerade as staffers.
“The attacker could take any action that the user could take on that network resource,” Microsoft warned.
The software giant has urged IT bosses to distribute a special root certificate for Windows Phone 8 and 7.8 devices accessing their networks; that certificate allows the handsets to confirm that any corporate wireless access points they’re connecting to are genuine before sending over the sensitive data.
Microsoft won’t issue a security update to fix the vulnerability, though, it said.
The certificate advisory follows the disclosure of a flaw in the Protected Extensible Authentication Protocol with Microsoft Challenge Handshake Authentication Protocol (version 2) used in Windows Phones for WPA2 authentication.
Explaining how Windows 8 phones can be immunised against the vuln, the software giant said the devices “can be configured to validate a network access point to help make sure the network is your company’s network before starting an authentication process. This can be done by validating a certificate that's on your company’s server. Only after validating the certificate is username and password information sent to the authentication server, so the phone can connect to the Wi-Fi network.”
Instructions on how to distribute the certificate, and why it's important, are here. ®