• Exploit Title: ATutor 2.2.4 'Backup' Remote Command Execution (CVE-2019-12170)
• Google Dork: inurl:/ATutor/login.php
• Date: 5/13/2019
• Exploit Author: liquidsky (Joseph McPeters)
• Vendor Homepage: https://atutor.github.io/
• Software Link: https://sourceforge.net/projects/atutor/files/latest/download
• Version: < 2.2.4 (Versions 2.2.4 and prior seem to be affected)
• Tested on: Windows 7 with XAMPP / Linux 3.16.0-4-amd64 with version 2.2.4 and 2.2.1
• Authors Site: http://incidentsecurity.com/atutor-2-2-4-backup-remote-command-execution/
• CVE: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-12170

ATutor 2.2.4 is vulnerable to arbitrary file uploads via the backup function that may result in remote command execution.

First login with the instructor account and select a course:

• #1 http://[atutor address]/atutor/bounce.php?course=1

Then navigate to "Manage"

• #2 http://[atutor address]/atutor/tools/index.php

Next select Backups/Upload

• #3 http://[atutor address]/atutor/mods/_core/backups/upload.php

From here a specially crafted backup zip file i.e "pwned_backup.zip" can be uploaded that will result in remote command execution.

The PoC arbitrary file can be found at: http://[atutor address]/atutor/content/1/pwned/poc.PhP

or

C:\xampp\htdocs\ATutor\content\1\pwned\poc.PhP

Note: The "1" in the address will change based on the course number and the "content" directory may be different. However by default the installation calls for the dir name to be "content". This has been tested on both linux/windows installations.

• A copy of the PoC zip file (pwned_backup.zip) can be downloaded: https://github.com/fuzzlove/ATutor-Instructor-Backup-Arbitrary-File

Screenshots included to show exact steps to successfully reenact exploit.

Update: There is no fix for this issue ATutor is no longer being maintained. [5/22/19]

• Directory traversal is also possible if the content directory is not in the webroot.

For more information on a directory traversal proof of concept check out: https://github.com/fuzzlove/ATutor-2.2.4-Language-Exploit/

    CVE-2019-12170: https://github.com/fuzzlove/ATutor-Instructor-Backup-Arbitrary-File
    CVE-2019-12169: https://github.com/fuzzlove/ATutor-2.2.4-Language-Exploit