Why are got and plt still present in linux static stripped binaries

In my studies, the Ubuntu one surprised me a lot, because in addition to these protections implanted by default, this system turns to take some openBSD solutions to be as user friendly and secure as possible. This relocation table is similar to the one in. Other sophisticated attacks like Return-oriented Programing are use to bypass these protection that make life difficult in an exploit process. To wit, consider the following code:.

Where is it used? Start it from the beginning? ELF Layout — execution view linking view source: NULL-terminated strings of names of symbols in.

The solution is to recompile the code with either -static compiler command-line option to create a static binaryor the following option:. This time, the address returned is the runtime address of foo in libfoo. This segment usually appears in a dynamic link library and it contains.

Depending on the compilers, uninitialized global variables could be stored in a nameness section called COMMON named after Fortran 77's "common blocks". November 30, at Note that there are two memory regions of KB with null permissions. After the address column, you have the offset within the file of the section, then you have the size in byte of each section, the section header size in byte, the required alignment, the Flags Read, Write, Executeand so on. The symbols will be defined as weak, so that multiple definitions are permitted.

Moreover, we have seen few protections and ways to bypass it, but the bits give us other difficulties. In this article, we will discover some important sections to target for any attack. This link provides general tips for building Glibc.

For dynamic binaries, this holds the full pathname of runtime linker ld. For dynamic binaries, this section is the symbol table of globally visible symbols. The uninitialized data segment containing statically-allocated variables. Basically, it plays with processes personality flags to mark a process to be out of ASLR. Format string vulnerabilities or heap overflow for example, are more easy to exploit with this protection, but this article is not finished yet and we will see another memory corruption mitigation technique.