56 lines
1.4 KiB
C
Executable File
56 lines
1.4 KiB
C
Executable File
#include <stdio.h>
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#include <sys/mman.h>
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#include <unistd.h>
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#include <stdlib.h>
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#include <elf.h>
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#include <sys/stat.h>
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#include <sys/types.h>
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#include <sys/procfs.h>
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#include <fcntl.h>
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int main(int argc, char** argv) {
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int f;
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static Elf32_Ehdr* header;
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printf(".: Elf corrupt :.\n");
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if(argc < 2){
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printf("Usage: %s file", argv[0]);
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return 1;
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}
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if((f = open(argv[1], O_RDWR)) < 0){
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perror("open");
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return 1;
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}
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//MAP_SHARED is required to actually update the file
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if((header = (Elf32_Ehdr *) mmap(NULL, sizeof(header), PROT_READ | PROT_WRITE, MAP_SHARED, f, 0)) == MAP_FAILED){
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perror("mmap");
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close(f);
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return 1;
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}
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printf("[*] Current header values:\n");
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printf("\te_shoff:%d\n\te_shnum:%d\n\te_shstrndx:%d\n",
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header->e_shoff, header->e_shnum, header->e_shstrndx);
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header->e_shoff = 0xffff;
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header->e_shnum = 0xffff;
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header->e_shstrndx = 0xffff;
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printf("[*] Patched header values:\n");
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printf("\te_shoff:%d\n\te_shnum:%d\n\te_shstrndx:%d\n",
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header->e_shoff, header->e_shnum, header->e_shstrndx);
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if(msync(NULL, 0, MS_SYNC) == -1){
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perror("msync");
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close(f);
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return 1;
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}
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close(f);
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munmap(header, 0);
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printf("You should no more be able to run \"%s\" inside GDB\n", argv[1]);
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return 0;
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} |