SQL Injection in SRS Simple Hits Counter Plugin for WordPress

Tenable has discovered a blind SQL injection vulnerability in the SRS Simple Hits Counter plugin for WordPress due to improper validation of user supplied input data. The root cause of the issue occurs in the srs_simple_hits_counter function which fails to validate the contents of the post_id variable. This variable value is used to form an SQL query in the update_views_visitors function.

An unauthenticated, remote attacker can exploit this issue via crafted requests to disclose potentially sensitive information from the WordPress database (e.g. admin password hash). We have verified this vulnerability is present when installed on Ubuntu Linux x64 and Windows x64.

For example:

In srs_simple_hits_counter, the post_id variable is set as such:

$post_id = $_GET['post_id'];

And then in update_views_visitors, a SQL query is constructed with this value:

$post_data = $wpdb->get_results("SELECT * FROM $table_name WHERE (srs_post_id = $post_id AND srs_date = '".$date."' )");

Proof of Concept

The PoC will attempt to exploit this issue to retrieve the admin password hash from the WordPress database by sending multiple specially crafted requests. The following is an example of how to use the PoC:

python3 blind_sqli_tra_2020_42.py http://192.168.1.195/wordpress