GLPI is an open-source asset and IT management software package that provides ITIL Service Desk features, licenses tracking and software auditing. In GLPI before version 9.5.4 there is an Insecure Direct Object Reference (IDOR) on Solutions. This vulnerability gives an unauthorized user the ability to enumerate GLPI items names (including users logins) using the knowbase search form (requires authentication). To Reproduce: Perform a valid authentication at your GLPI instance, Browse the ticket list and select any open ticket, click on Solution form, then Search a solution form that will redirect you to the endpoint /glpi/front/knowbaseitem.php?item_itemtype=Ticket&item_items_id=18&forcetab=Knowbase$1, and the item_itemtype=Ticket parameter present in the previous URL will point to the PHP alias of glpi_tickets table, so just replace it with Users to point to glpi_users table instead; in the same way, item_items_id=18 will point to the related column id, so changing it too you should be able to enumerate all the content which has an alias. Since such id(s) are obviously incremental, a malicious party could exploit the vulnerability simply by guessing-based attempts.
The system’s authorization functionality does not prevent one user from gaining access to another user’s data or record by modifying the key value identifying the data.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Glpi | Glpi-project | * | 9.5.4 (excluding) |
| Glpi | Ubuntu | esm-apps/xenial | * |
| Glpi | Ubuntu | trusty | * |
| Glpi | Ubuntu | xenial | * |
Retrieval of a user record occurs in the system based on some key value that is under user control. The key would typically identify a user-related record stored in the system and would be used to lookup that record for presentation to the user. It is likely that an attacker would have to be an authenticated user in the system. However, the authorization process would not properly check the data access operation to ensure that the authenticated user performing the operation has sufficient entitlements to perform the requested data access, hence bypassing any other authorization checks present in the system. For example, attackers can look at places where user specific data is retrieved (e.g. search screens) and determine whether the key for the item being looked up is controllable externally. The key may be a hidden field in the HTML form field, might be passed as a URL parameter or as an unencrypted cookie variable, then in each of these cases it will be possible to tamper with the key value. One manifestation of this weakness is when a system uses sequential or otherwise easily-guessable session IDs that would allow one user to easily switch to another user’s session and read/modify their data.