New Exploit Methods against Ptmalloc of GLIBC

GNU Libc (GLIBC) is the standard C runtime library of most Linux distributions for PC and servers. There used to be many memory corruption exploit techniques against ptmalloc, the default heap allocator of GLIBC. But the widely deployment of mitigations like NX and ASLR on modern operating systems and continuous patching to ptmalloc effectively obsolete most of these techniques. We believe security always comes from design, and think the basic design of ptmalloc is obsolete and fundamentally flawed. In this paper, we present some new exploit methods against ptmalloc along with proof of concept code. We also discuss the feasibility of former exploit techniques in modern environments and compare them to our methods.