ATutor 2.2 PHP Code Injection
Posted on 05 November 2015
--------------------------------------------------------------- ATutor <= 2.2 (edit_marks.php) PHP Code Injection Vulnerability --------------------------------------------------------------- [-] 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
