Relevanssi 3.5.12 / 3.6.0 SQL Injection

Relevanssi versions 3.5.12 and 3.6.0 suffer from a remote SQL injection vulnerability.

MD5 | 410a758b0c586d1e5043901f4f2ce80d

Software: Relevanssi
Version: 3.5.12,3.6.0
Advisory report:
CVE: Awaiting assignment
CVSS: 8.5 (High; AV:N/AC:L/Au:S/C:C/I:C/A:N)

SQLi in Relevanssi might allow an admin to read contents of database

If logged in as an administrator on any site, you can go to Settings > Relevanssi Premium and potentially extract all values in the database including password hashes and user activation tokens.
This is achieved by a SQL injection based on the fact that some of the configuration options are appended into a SQL query in a unsafe way.
The configuration page contains the following code, that allows the user to set the option relevanssi_post_type_weights to any value:
function update_relevanssi_options() {
foreach ($_REQUEST as $key => $value) {
if (substr($key, 0, strlen(\'relevanssi_weight_\')) == \'relevanssi_weight_\') {
$type = substr($key, strlen(\'relevanssi_weight_\'));
$post_type_weights[$type] = $value;
if (count($post_type_weights) > 0) {
update_option(\'relevanssi_post_type_weights\', $post_type_weights);
Now when a search is made, the function relevanssi_search is called, this appends the user controled value into the SQL query:
$post_type_weights = get_option(\'relevanssi_post_type_weights\');


!empty($post_type_weights[\'post_tag\']) ? $tag = $post_type_weights[\'post_tag\'] : $tag = $relevanssi_variables[\'post_type_weight_defaults\'][\'post_tag\'];

!empty($post_type_weights[\'category\']) ? $cat = $post_type_weights[\'category\'] : $cat = $relevanssi_variables[\'post_type_weight_defaults\'][\'category\'];

$query = \"SELECT relevanssi.*, relevanssi.title * $title_boost +
relevanssi.content + relevanssi.comment * $comment_boost +
relevanssi.tag * $tag + * $link_boost + + relevanssi.category * $cat + relevanssi.excerpt +
relevanssi.taxonomy + relevanssi.customfield + relevanssi.mysqlcolumn AS tf
FROM $relevanssi_table AS relevanssi $query_join
WHERE $term_cond $query_restrictions\";

Proof of concept

Visit /wp-admin/options-general.php?page=relevanssi%2Frelevanssi.php
Assign 0.75\' (the default value plus a single quote at the end) to aTag weighta
Press aSave the optionsa
Visit /?s=test
The logs should contain the following error because of the syntax error we introduced: aWordPress database error You have an error in your SQL syntaxa

Note: while itas possible to inject syntax errors, itas currently unknown whether this bug can be used to inject anything that would be useful to an attacker.

Upgrade to version 3.6.1 or later.

Disclosure policy
dxw believes in responsible disclosure. Your attention is drawn to our disclosure policy:

Please contact us on [email protected] to acknowledge this report if you received it via a third party (for example, [email protected]) 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.


2017-10-02: Discovered
2017-10-02: Reported to vendor via email
2017-10-03: First response from vendor
2017-10-03: Version 3.6.1 released which contains a fix for this bug

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

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