Apache Superset - Elevation of Privilege

Overview

An attacker with access to the SQL Lab and the ab_user and ab_user_role tables can elevate his privileges to become administrator.

Details

On a more general level, diverse tables who are supposed to be only readable can be modified using the WITH … AS and RETURNING keywords. Modification of the table key_value can also be done, which could lead to a Remote Code Execution (cf. "V7 - Insecure deserialization leading to remote code execution" report vulnerability).

Proof of Concept

Some tables are supposed to accept only SELECT requests from the SQL tab.

• Attempt to create a new user injected_admin into the ab_user table: PoC_1

But this protection can be bypassed by using the WITH … AS () syntax with RETURNING value after the INSERT / UPDATE / DELETE query. INSERT query accepted by the database due to the use of WITH … AS ( … RETURNING ) syntax: WITH a AS ( INSERT INTO ab_user (id, first_name, last_name, username, email, password) VALUES (2, ‘injected_admin’, ‘injected_admin’, ‘injected_admin’, ‘[email protected]’, ‘{PASSWORD_HASH}’) RETURNING id ) SELECT * FROM a; PoC_2

• injected_admin added to the ab_user table: PoC_3

This method can also be used with UPDATE or DELETE request. A user with access to SELECT on the tables ab_user_role can escalate his privilege to become administrator.

• Locating the ID of the user ‘Auditeur B’, who has no rights and is not an admin. The request is done being ‘Auditeur B’: PoC_4
• Locating the rows that keep the role of the user ‘Auditeur B’. The row 36 stores the value 3, indicating the role ‘Alpha’ for ‘Auditeur B’: PoC_5
• Modification of the row 36 with an UPDATE request embedded in a WITH request: PoC_6
• ‘Auditeur B’ role has been changed to Admin: PoC_7