ATutor 2.2 PHP Code Injection

`---------------------------------------------------------------  
ATutor <= 2.2 (edit_marks.php) PHP Code Injection Vulnerability  
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[-] Software Link:  
  
http://www.atutor.ca/  
  
  
[-] Affected Versions:  
  
Version 2.2 and prior versions.   
  
  
[-] Vulnerability Description:  
  
The vulnerable code is located in the /mods/_standard/gradebook/edit_marks.php script:  
  
54. if (isset($_GET['asc']))  
55. {  
56. $order = 'asc';  
57. $order_col = $addslashes($_GET['asc']);  
58. }  
59. else if (isset($_GET['desc'])) {  
60. $order = 'desc';  
61. $order_col = $addslashes($_GET['desc']);  
  
[...]  
  
185. if ((isset($_GET["asc"]) || isset($_GET["desc"])) && $order_col <> "name")  
186. {  
187. $sort = '$grades['.$order_col.'], SORT_'.strtoupper($order).', $selected_students ...  
188.   
189. foreach($selected_tests as $test)  
190. {  
191. if ($test["gradebook_test_id"] <> $order_col)  
192. $sort .= ', $grades['.$test["gradebook_test_id"].'], SORT_'.strtoupper($order);  
193. }  
194. $sort='array_multisort('.$sort.');';  
195. eval($sort);  
196. }  
  
User input passed through the "asc" or "desc" GET parameters is not properly sanitized before being used in a  
call to the "eval()" function at line 195. This can be exploited to inject and execute arbitrary PHP code.  
Successful exploitation of this vulnerability requires an account with the "AT_PRIV_GRADEBOOK" privilege.  
  
  
[-] Solution:  
  
No official solution is currently available.  
  
  
[-] Disclosure Timeline:  
  
[06/10/2014] - Vendor notified  
[09/10/2014] - Vendor response stating this issue has been added to the bug tracker and it is relatively minor  
[13/10/2014] - Vendor replied saying he is not able to reproduce the issue and asked for further details  
[29/10/2014] - Further exploitation details have been provided to the vendor  
[11/11/2014] - Vendor replied saying he still is not able to reproduce the issue and asked for fix suggestions  
[11/11/2014] - Some fix suggestions have been provided to the vendor  
[30/09/2015] - CVE number requested  
[05/10/2015] - CVE number assigned  
[06/10/2015] - After one year still no official solution available  
[04/11/2015] - Public disclosure  
  
  
[-] CVE Reference:  
  
The Common Vulnerabilities and Exposures project (cve.mitre.org)  
has assigned the name CVE-2015-7712 to this vulnerability.  
  
  
[-] Credits:  
  
Vulnerability discovered by Egidio Romano.  
  
  
[-] Original Advisory:  
  
http://karmainsecurity.com/KIS-2015-08  
  
  
`