CVE-2024-2342: Simply Schedule Appointments SQLi Flaw

CVE-2024-2342 Overview

CVE-2024-2342 is an authenticated SQL injection vulnerability in the Simply Schedule Appointments booking plugin for WordPress, developed by nsquared. The flaw affects all versions up to and including 1.6.7.7. The vulnerability resides in the handling of the customer_id parameter, which lacks proper escaping and is used in an SQL query without sufficient preparation. Authenticated users with contributor-level access or higher can append additional SQL statements to existing queries. Successful exploitation allows extraction of sensitive data from the WordPress database, including user credentials and configuration secrets.

Critical Impact
Authenticated contributors can execute arbitrary SQL statements against the WordPress database, exposing user data, password hashes, and session tokens.

Affected Products

Nsquared Simply Schedule Appointments plugin for WordPress
All versions up to and including 1.6.7.7
WordPress installations with the plugin activated and contributor-or-higher accounts provisioned

Discovery Timeline

2024-04-09 - CVE-2024-2342 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2024-2342

Vulnerability Analysis

The vulnerability is a classic SQL injection flaw [CWE-89] rooted in unsafe database query construction. The plugin accepts the customer_id parameter from an authenticated request and concatenates it into a SQL statement without using prepared statements or parameter binding. Because the input is not escaped or type-cast, attacker-controlled SQL syntax reaches the database engine intact.

The attack requires contributor-level authentication, which lowers the barrier significantly on multi-author WordPress sites and membership platforms. Contributor accounts are commonly granted to guest writers, freelancers, and community submitters, making this privilege threshold trivial to satisfy in many deployments.

Exploitation impact spans confidentiality, integrity, and availability. Attackers can exfiltrate WordPress wp_users records including password hashes, dump plugin configuration secrets, or manipulate booking records tied to customer PII.

Root Cause

The root cause is insufficient input sanitization combined with the absence of wpdb::prepare() around a SQL query that consumes the customer_id parameter. The plugin trusted the parameter as a numeric identifier but never enforced that assumption through casting or parameterized placeholders.

Attack Vector

An authenticated attacker with contributor privileges submits a crafted request to a plugin endpoint that consumes customer_id. The payload appends a UNION SELECT or subquery clause to the existing SQL statement. The database returns injected results through the plugin's response, enabling data extraction. See the Wordfence Vulnerability Report for further technical detail.

Detection Methods for CVE-2024-2342

Indicators of Compromise

Unusual customer_id values in web server access logs containing SQL keywords such as UNION, SELECT, SLEEP, or CONCAT.
Unexpected slow queries or long response times on requests targeting Simply Schedule Appointments REST endpoints.
New or modified rows in wp_users or wp_usermeta following requests from contributor-tier accounts.
Outbound HTTP requests from the web host correlating with database read spikes on the WordPress schema.

Detection Strategies

Enable WordPress query logging or database audit logging and alert on plugin requests containing SQL metacharacters in the customer_id parameter.
Deploy a Web Application Firewall (WAF) rule that inspects requests to /wp-json/ssa/ and /wp-admin/admin-ajax.php for SQL injection patterns.
Correlate contributor-account activity with unusual database read volumes using SIEM analytics.

Monitoring Recommendations

Monitor authentication logs for newly created contributor accounts followed by immediate plugin interactions.
Track WordPress plugin version inventory across managed sites and flag installations at or below version 1.6.7.7.
Alert on any HTTP 500 responses from Simply Schedule Appointments endpoints, which can indicate probing for injection points.

How to Mitigate CVE-2024-2342

Immediate Actions Required

Upgrade the Simply Schedule Appointments plugin to version 1.6.7.8 or later on every WordPress site.
Audit all contributor, author, and editor accounts and disable any that are unused or suspicious.
Rotate WordPress secret keys in wp-config.php and force password resets if compromise is suspected.
Review database access logs for the past 90 days for signs of exploitation.

Patch Information

The vendor released a fix in the plugin trunk that adds proper escaping and query preparation for the customer_id parameter. Review the WordPress Plugin Changeset for the exact code changes. Site operators should update through the WordPress Plugins dashboard or via WP-CLI.

Workarounds

If patching cannot occur immediately, deactivate the Simply Schedule Appointments plugin until it is updated.
Restrict contributor-tier account creation and require administrator approval for new registrations.
Deploy virtual patching through a WAF that blocks SQL metacharacters in the customer_id parameter.

bash

# Update the plugin via WP-CLI
wp plugin update simply-schedule-appointments --version=1.6.7.8

# Verify installed version across a multisite fleet
wp plugin get simply-schedule-appointments --field=version