Microsoft Windows Live Messenger Client 8.5.1 and earlier, when MSN Protocol Version 15 (MSNP15) is used over a NAT session, allows remote attackers to discover intranet IP addresses and port numbers by reading the (1) IPv4InternalAddrsAndPorts, (2) IPv4Internal-Addrs, and (3) IPv4Internal-Port header fields.

Buffer overflow in the GDI engine in Windows Live Messenger, as used for Windows MSN Live 8.1, allows user-assisted remote attackers to cause a denial of service (application crash or system crash) and possibly execute arbitrary code by placing a malformed file in a new folder under the Sharing Folders path, and triggering a synchronize operation through the Windows MSN Live online service, possibly related to extended file attributes and possibly related to an incomplete fix for MS07-046, as demonstrated by a (1) .jpg, (2) .gif, (3) .wmf, (4) .doc, or (5) .ico file.