DieHard

DieHard is an application that eliminates or greatly reduces the likelihood of a class of bugs and security vulnerabilities called memory errors.

DieHard prevents certain kinds of errors from happening at all. It also reduces the probability that a bug will have any effect at all. DieHard works by randomly locating program objects far apart from each other in memory.

This scattering of memory objects all over memory not only makes some errors unlikely to happen, it also makes it virtually impossible for a hacker to know where vulnerable parts of the program's data are. This thwarts a wide class of exploits.

DieHard prevents invalid and multiple frees and heap corruption, and probabilistically avoids buffer overflows, dangling pointer errors, and uninitialized reads.

DieHard works in two modes: standalone and replicated. The standalone version replaces the memory manager with the DieHard randomized memory manager.

This randomization increases the odds that buffer overflows will have no effect, and reduces the risk of dangling pointers. The replicated version provides greater protection against errors by running several instances of the application simultaneously and voting on their output.

Because each replica is randomized differently, each replica will likely have a different output if it has an error, and some replicas are likely to run correctly despite the error.

The standalone version works for Linux, Solaris, and Windows, while the replicated version currently only supports Linux or Solaris console applications.

DieHard currently protects Firefox on Windows XP and Vista - to use with Vista, right-click on the desktop shortcut, and set the Properties so it runs in Windows XP SP2 compatibility mode. DieHard works with Firefox versions 1.5.0.9 and higher, and 2.0.0.1.

Limitations:

￭ Free for non-commercial use