Fully patched versions of Windows XP and 2000 have another critical vulnerability, which can be exploited by hackers to launch malicious attacks.

Security firm Secunia reported that the vulnerability, which Secunia rates as "moderately critical" is the result of a boundary error in the "UpdateFrameTitleForDocument()" function of the CFrameWnd class in mfc42.dll. The vulnerability can be exploited to cause a stack-based buffer overflow error, which occurs by passing an overly long title string argument to the vulnerable function.

If exploited, the vulnerability can open the door for hackers to launch remote code execution attacks, aimed at taking control of a user's computer and stealing sensitive data.
The only real way to hack a system is to get a user to download a bit of code using social engineering tricks, but that does not really make it less likely to be a problem. The vulnerability has appeared in fully patched versions of Windows 2000 Professional SP4 and Windows XP SP2/SP3, although other versions may also be affected.

Microsoft has not patched the flaw and not yet issued an advisory warning users about the flaw. However it is getting increasingly tired of having to deal with Windows XP and 2000 flaws. The two operating systems are now ancient and much harder to protect than modern operating systems such as Vista and Windows 7.