The MWR Labs group at MWR Info Security is running a series of articles comparing Linux distributions from a security point of view. Part 1: user space memory protection looks at protection against memory corruption attacks, while Part 2 - into the kernel examines kernel security settings. "The notable exceptions in the results are Fedora and Ubuntu. Both distributions do not allow the ability to write code to a certain memory region and then execute it. This can be observed from the results of the first five tests. Fedora goes one step further and also prevents the bss, data and heap sections from being marked as executable using the 'mprotect' system call. It should be noted that there would still be numerous other memory regions where an attacker could upload their code and then use the 'mprotect' function to mark it as executable."