SiYuan: Authorization Bypass Allows Arbitrary SQL Execution via Search API

SiYuan is a personal knowledge management system. Versions 3.6.0 and below contain an authorization bypass vulnerability in the /api/search/fullTextSearchBlock endpoint. When the method parameter is set to 2, the endpoint passes user-supplied input directly as a raw SQL statement to the underlying SQLite database without any authorization or read-only checks. This allows any authenticated user — including those with the Reader role — to execute arbitrary SQL statements (SELECT, DELETE, UPDATE, DROP TABLE, etc.) against the application's database. This is inconsistent with the application's own security model: the dedicated SQL endpoint (/api/query/sql) correctly requires both CheckAdminRole and CheckReadonly middleware, but the search endpoint bypasses these controls entirely. This issue has been fixed in version 3.6.1.