There are reported defects in the Windows Phone 7.5 of an SMS bug that acts as a hacking medium. This in turn leads to reduced functionality of the Windows Phone 7.5. This makes things difficult for the users.
There are reports that when an untrustworthy sms is sent to a Windows Phone 7.5, the Windows Phone restarts automatically and terminates the messaging process immediately.
There are also reports that a chat message from Facebook or a windows messenger notification reportedly activates this malicious sms. Thus to protect itself, the Windows Phone automatically resets.
One major disadvantage of this is that Hackers can easily take control of the host system thereby destroying the system completely. This bug allows the hackers to even make calls, send sms and implement other negative manipulations. Thus, this becomes a major issue.
The latest Android Smartphones as well as Apple's iPhone are also victims of this flaw.
Almost all major tech giants have addressed this issue as it becomes a major integrity threat. Many other companies are following suit and hope to address the issue as soon as possible.