Details
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Software: Post Indexer
Version: 3.0.6.1
Homepage: https://premium.wpmudev.org/project/post-indexer/
Advisory report: https://security.dxw.com/advisories/sql-injection-in-post-indexer-allows-super-admins-to-read-the-contents-of-the-database/
CVE: Awaiting assignment
CVSS: 4 (Medium; AV:N/AC:L/Au:S/C:P/I:N/A:N)

Description
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SQL Injection in Post Indexer allows super admins to read the contents of the database

Vulnerability
================



Post Indexer does not use prepared queries in many cases and in some of its database calls it uses backticks (`). These are not automatically escaped by WordPress, thus leading to the possibility of SQLA injection.
In other places in the code it simply takes user controlled values and adds them to SQLA queries.
An example of this is remove_post_older_than:



// classes/class.model.php line 589
function remove_posts_older_than( $unit, $period ) {
    // ...
    $sql = $this->db->prepare( \"SELECT BLOG_ID, ID FROM {$this->network_posts} WHERE DATE_ADD(post_date, INTERVAL %d \" . $period . \") < CURRENT_DATE() LIMIT %d\", $unit, PI_CRON_TIDY_DELETE_LIMIT );
    $posts = $this->db->get_results( $sql );
    // ...
}




The value of $period is user-controlled and could easily be replaced with SQL:



// classes/cron.postindexerrebuild.php line 310
function process_tidy_agedposts($DEBUG = false) {
    // ...
    // The default is to remove posts from the index when they are over a year old
    $agedposts = get_site_option( \'postindexer_agedposts\', array( \'agedunit\' => 1, \'agedperiod\' => \'year\' ) );
    // ...
    $this->model->remove_posts_older_than( $agedposts[\'agedunit\'], $agedposts[\'agedperiod\'] );
    // ...
}



To exploit this vulnerability you need to be a super admin.




Proof of concept
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Mitigations
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Upgrade to version 3.0.6.2 or later.

Disclosure policy
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dxw believes in responsible disclosure. Your attention is drawn to our disclosure policy: https://security.dxw.com/disclosure/

Please contact us on security@dxw.com to acknowledge this report if you received it via a third party (for example, plugins@wordpress.org) as they generally cannot communicate with us on your behalf.

This vulnerability will be published if we do not receive a response to this report with 14 days.

Timeline
================

2016-11-01: Discovered
2016-11-14: Reported to plugin author viaA https://premium.wpmudev.org/contact/
2016-11-14:A Plugin author responded
2016-11-17: Confirmed that version 3.0.6.2 fixes the issue
2016-11-17:A Requested CVE
2016-11-17:A Advisory published



Discovered by dxw:
================
Glyn Wintle
Please visit security.dxw.com for more information.