GHSA-g8p8-94f2-28gr Admidio Exposes Cross-Organization Member Data via Permission Check Mismatch in contacts_data.php

• Packagist admidio/admidio: < 5.0.9 → fixed in 5.0.9

Summary The `contacts_data.php` endpoint uses a weaker permission check (`isAdministratorUsers()`, requiring only `rol_edit_user=true`) than the frontend UI (`contacts.php`) which correctly requires the stronger `isAdministrator()` (requiring `rol_administrator=true`) and the `contacts_show_all` system setting. A user manager who is not a full administrator can directly request `contacts_data.php?mem_show_filter=3` to retrieve all user records across all organizations in the Admidio instance, bypassing multi-tenant organization isolation. Details The frontend page `contacts.php` and the backend data endpoint `contacts_data.php` have mismatched authorization checks for the "show all organizations" filter (`mem_show_filter=3`). Frontend guard at `modules/contacts/contacts.php:80`: ```php if ($gCurrentUser->isAdministrator() && $gSettingsManager->getBool('contacts_show_all')) { // Only then is filter=3 ("All Organizations") shown in the dropdown $selectBoxValues = array( ... '3' => array('3', $gL10n->get('SYS_ALL_CONTACTS'), $gL10n->get('SYS_ALL_ORGANIZATIONS')) ); } ``` This correctly requires both `isAdministrator()` (`rol_administrator=true`) AND the `contacts_show_all` setting. Backend check at `modules/contacts/contacts_data.php:235`: ```php } elseif (($getMembersShowFilter === 3) && $gCurrentUser->isAdministratorUsers()) { $mainSql = $contactsListConfig->getSql( array( 'showAllMembersDatabase' => true, ... ) ); ``` This only requires `isAdministratorUsers()` which checks `rol_edit_user=true` — a weaker permission available to non-admin "user manager" roles. The `contacts_show_all` setting is never checked. The critical difference between the two methods (from `src/Users/Entity/User.php`): • `isAdministrator()` (line 1507): checks the `rol_administrator` flag — full system administrator • `isAdministratorUsers()` (line 1625): checks `rol_edit_user` right — user management module access only When `showAllMembersDatabase=true` reaches `ListConfiguration::getSql()` (at `src/Roles/Entity/ListConfiguration.php:1022-1028`), the generated SQL removes ALL organization filtering: ```php } elseif ($optionsAll['showAllMembersDatabase']) { $sql = 'SELECT DISTINCT ' . $sqlMemLeader . $sqlIdColumns . $sqlColumnNames . ' FROM ' . TBL_USERS . ' ' . $sqlJoin . ' WHERE usr_valid = true ' . $sqlWhere . $sqlOrderBys; } ``` Compare with the default query which includes `cat_org_id = $gCurrentOrgId` to restrict results to the current organization. The cross-org indicator subqueries at line 169 do correctly check `isAdministrator()`, so the `member_other_orga` columns return 0 — but this only affects display indicators, not the actual user data returned. PoC Prerequisites: An Admidio instance with at least two organizations sharing the same database. A user account in Organization A assigned to a role with `rol_edit_user=1` but `rol_administrator=0`. Step 1: Log in as the user manager account and capture the session cookie. Step 2: Request all users across all organizations by directly calling the data endpoint: ```bash curl -s -b 'PHPSESSID=' \ 'https://target/adm_program/modules/contacts/contacts_data.php?mem_show_filter=3&draw=1&start=0&length=100&search%5Bvalue%5D=' ``` Expected behavior: The request should be rejected or return only current-organization users, since the user is not a full administrator and the frontend never offers filter=3 to non-administrators. Actual behavior: The endpoint returns a JSON response containing all users from ALL organizations in the database, including: • User UUIDs (`usr_uuid`) • Login names (`login_name`) • Email addresses (`member_email`) • All configured profile fields (names, addresses, phone numbers, etc.) Step 3: Verify that users from Organization B (where the attacker has no membership) appear in the results by checking the `member_this_orga` field — it will be `0` for cross-org users. Impact In multi-organization Admidio deployments (the primary use case for organization isolation), a user manager in one organization can exfiltrate the complete member directory of all other organizations sharing the same database. Exposed data includes: • Full names and all configured profile fields • Email addresses • Login names (useful for credential attacks) • User UUIDs (useful for targeting other API endpoints) This completely bypasses the multi-tenant organization isolation boundary. The `contacts_show_all` admin setting (intended to control this feature) is also bypassed, meaning even instances where administrators have explicitly disabled cross-org viewing are affected. Recommended Fix Change line 235 in `modules/contacts/contacts_data.php` to match the frontend guard at `contacts.php:80`: ```php // Before (vulnerable): } elseif (($getMembersShowFilter === 3) && $gCurrentUser->isAdministratorUsers()) { // After (fixed): } elseif (($getMembersShowFilter === 3) && $gCurrentUser->isAdministrator() && $gSettingsManager->getBool('contacts_show_all')) { ``` Additionally, as defense-in-depth, add an early rejection at the top of the file (after line 59) to block the filter value entirely for unauthorized users: ```php if ($getMembersShowFilter === 3 && (!$gCurrentUser->isAdministrator() || !$gSettingsManager->getBool('contacts_show_all'))) { $getMembersShowFilter = 0; // Fall back to default } ```