: Many users encounter the error message "Windows was unable to find a certificate to log you on to the network." Installing this patch often resolves this by adding the correct WPA2 and WPA2-PSK options to the wireless properties menu.

Before KB917021 was applied, an attacker could craft a .lnk (shortcut) file or a malicious folder with a modified icon resource. If a victim simply browsed to the folder containing the file (without even opening it), Windows Explorer would attempt to parse the malformed icon data. This parsing could trigger a buffer overflow, granting the attacker the ability to execute arbitrary code with the user’s own privileges.