Masterstudy Lms Wordpress Plugin For Online Courses And Education
CVE-2026-4817
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EUVD-2026-23338
MEDIUM
Severity by source
AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
Lifecycle Timeline
4DescriptionCVE.org
The MasterStudy LMS WordPress Plugin for Online Courses and Education plugin for WordPress is vulnerable to Time-based Blind SQL Injection via the 'order' and 'orderby' parameters in the /lms/stm-lms/order/items REST API endpoint in versions up to and including 3.7.25. This is due to insufficient input sanitization combined with a design flaw in the custom Query builder class that allows unquoted SQL injection in ORDER BY clauses. When the Query builder detects parentheses in the sort_by parameter, it treats the value as a SQL function and directly concatenates it into the ORDER BY clause without any quoting. While esc_sql() is applied to escape quotes and backslashes, this cannot prevent ORDER BY injection when the values themselves are not wrapped in quotes in the resulting SQL statement. This makes it possible for authenticated attackers, with subscriber-level access and above, to append arbitrary SQL queries via the ORDER BY clause to extract sensitive information from the database including user credentials, session tokens, and other confidential data through time-based blind SQL injection techniques.
AnalysisAI
Time-based blind SQL injection in MasterStudy LMS WordPress plugin up to version 3.7.25 allows authenticated subscribers and above to extract sensitive database information including user credentials and session tokens via unquoted ORDER BY clause injection in the /lms/stm-lms/order/items REST API endpoint. The vulnerability stems from a custom Query builder that concatenates user-supplied sort parameters containing parentheses directly into SQL ORDER BY clauses without proper quoting, bypassing the plugin's use of esc_sql(). CVSS score of 6.5 reflects network-accessible exploitation requiring low privilege (subscriber-level) authentication and no user interaction.
Technical ContextAI
The MasterStudy LMS plugin implements a custom Query builder class (Query.php, line 676) that constructs SQL ORDER BY clauses dynamically. When the 'sort_by' parameter contains parentheses, the builder interprets the value as a SQL function and directly concatenates it into the ORDER BY clause without wrapping the value in quotes. While the code applies esc_sql() to escape quotes and backslashes, this function is ineffective for ORDER BY injection when values are not quoted in the resulting SQL statement-it only escapes quote characters but does not prevent SQL syntax injection when unquoted values are used. The vulnerability is accessible through the REST API endpoint /lms/stm-lms/order/items, called from route.php (line 16) and used by StmStatistics model (lines 202, 238). The root cause is classified as CWE-89 (Improper Neutralization of Special Elements used in an SQL Command) stemming from insufficient input sanitization and a fundamental design flaw in SQL construction logic that fails to validate or sanitize sort parameters against SQL syntax.
RemediationAI
Upgrade MasterStudy LMS plugin to version 3.7.26 or later immediately. The patch is available via the WordPress plugin repository and addresses the SQL injection by properly quoting sort parameters in the Query builder's ORDER BY clause construction logic. If immediate upgrade is not feasible, disable the REST API endpoint /lms/stm-lms/order/items by adding a code snippet to functions.php or using a REST API access control plugin to restrict access to authenticated administrators only, reducing the attack surface from any subscriber to administrators exclusively. This workaround has the trade-off of disabling sorting functionality in the affected endpoint for non-admin users and should be considered temporary only. Do not rely solely on esc_sql() for ORDER BY clause protection; proper parameterization or whitelist validation of sort parameters is required. Monitor database query logs for time-based SQL injection patterns (queries with SLEEP() or BENCHMARK() functions in ORDER BY clauses).
Same weakness CWE-89 – SQL Injection
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External POC / Exploit Code
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