Here is some text taken from a site I went to when I did a search for MSN 7.0 vulnerabilities
s in February, Microsoft also published critical patches for Microsoft Office and MSN Messenger. Two bulletins dealt with bugs in Word and in Microsoft's MSN Messenger 6.2.
MS05-022 takes care of a loose screw in the latter, which stumbles when asked to process an improperly-sized GIF image or emoticon. Hackers could send such images via IM, and snatch control of the PC, said Microsoft.
One advantage for early adopters is that the just released v. 7.0 of Messenger is immune to the flaw. (Oddly enough, however, users of the beta version of MSN Messenger 7.0 are at risk, and should upgrade as soon as possible.)
Here too is something from Symantec
http://sarc.com/avcenter/security/Content/13114.html
This was just one of the vulnerabilities, there was 18 found in total and patches made for them