Heap security has been a major concern since the past two decades. Recently many methods have been proposed to secure heap i.e. to avoid heap overrun and attacks. The paper describes a method suggested to secure heap at the operating system level. Major emphasis is given to Solaris operating system's dynamic memory manager. When memory is required dynamically during runtime, the SysVmalloc acts as a memory allocator.Vmalloc allocates the chunks of memory in the form of splay tree structure. A self adjusting binary tree structure is reviewed in the paper, moreover major security issue to secure heap area is also suggested in the paper