SRC-2016-0012 : ATutor LMS confirm ‘UPDATE’ Type Juggling Authentication Bypass Vulnerability
ATutor 2.2.1 is confirmed, other versions may also be affected.
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 updating a members email address. The code uses a loose comparison when comparing the supplied ‘m’ variable with an influenced string value. An attacker can update a members email address and reset the password. Finally, an attacker can combine this with another vulnerability to achieve remote code execution.
ATutor has issued an update to correct this vulnerability. More details can be found at: https://github.com/atutor/ATutor/commit/2eed42a74454355eddc7fc119e67af40dba1a94c
- 2016-02-24 – Vulnerability reported to vendor
- 2016-02-24 – CVE requested and rejected
- 2016-02-25 – Vendor confirmed issue
- 2016-03-07 – Vendor releases a patch
- 2016-03-08 – Coordinated public release of advisory
Proof of Concept:
This vulnerability was discovered by Steven Seeley of Source Incite