RealNetworks Helix Universal Server v9.0 and below for Windows, FreeBSD, HP-UX, AIX, Linux, Sun Solaris 2.7 & 2.8 contains buffer overflows which can cause code to be executed as SYSTEM over tcp port 554.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/30631/real.helix.9.0.txt
Source: https://packetstormsecurity.com/files/30631/real.helix.9.0.txt.html