Integer overflow in the AgentX::receive_agentx function in AgentX++ 1.4.16, as used in RealNetworks Helix Server and Helix Mobile Server 11.x through 13.x and other products, allows remote attackers to execute arbitrary code via a request with a crafted payload length.
http://www.vupen.com/english/advisories/2010/0889
http://www.securityfocus.com/bid/39490
http://www.realnetworks.com/uploadedFiles/Support/helix-support/SecurityUpdate041410HS.pdf