Buffer overflow in NetSupport Manager (NSM) Client 10.00 and 10.20 and NetSupport School Student (NSS) 9.00 allows remote NSM servers to cause a denial of service or possibly execute arbitrary code via crafted data in the configuration exchange phase of an initial connection setup. NOTE: a vendor statement which is too vague to be sure that it is for this particular issue says that only a denial of service is possible.