SRC-2016-0008 : ATutor LMS confirm ‘SELECT’ Type Juggling Authentication Bypass Vulnerability



CVSS Score:

7.5, (AV:N/AC:L/Au:N/C:P/I:P/A:P)

Affected Vendors:


Affected Products:

ATutor 2.2.1 is confirmed, other versions may also be affected.

Vulnerability Details:

This vulnerability allows remote attackers to bypass the authentication mechanism on vulnerable installations of ATutor.

The specific flaw exists in the ‘confirm.php’ script when performing an automated login. The code uses a loose comparison when comparing the supplied ‘code’ variable with an influenced string value. An attacker can combine this with other vulnerabilities to achieve remote code execution.

Vendor Response:

ATutor has issued an update to correct this vulnerability. More details can be found at:

Disclosure Timeline:

  • 2016-03-17 – Vulnerability reported to vendor
  • 2016-03-17 – Vendor confirmed issue
  • 2016-03-19 – Vendor releases a patch
  • 2016-03-19 – Coordinated public release of advisory

Proof of Concept:


This vulnerability was discovered by Steven Seeley of Source Incite