Title: Undefined index: HTTP_REFERER in DbCache_WpdbInjection_QueryCaching.php
Last modified: November 1, 2016

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# Undefined index: HTTP_REFERER in DbCache_WpdbInjection_QueryCaching.php

 *  [patjk](https://wordpress.org/support/users/patjk/)
 * (@patjk)
 * [9 years, 7 months ago](https://wordpress.org/support/topic/undefined-index-http_referer-in-dbcache_wpdbinjection_querycaching-php/)
 * Hello,
    In addition to W3C, I just installed WordFence as I was having the server
   crash due to bruteforce attacks on wp-login and xmlrcp.php. During a scan with
   WordFence, this came up: [Nov 01 03:02:56] Notice: Undefined index: HTTP_REFERER
   in /home/domain/public_html/wp-content/plugins/w3-total-cache/DbCache_WpdbInjection_QueryCaching.
   php on line 366 Notice: Undefined index: HTTP_REFERER in /home/eas
 * What’s the best way to resolve this?
 * Thanks.

Viewing 3 replies - 1 through 3 (of 3 total)

 *  [nigro.simone](https://wordpress.org/support/users/nigrosimone/)
 * (@nigrosimone)
 * [9 years, 7 months ago](https://wordpress.org/support/topic/undefined-index-http_referer-in-dbcache_wpdbinjection_querycaching-php/#post-8380669)
 * try to change /wp-content/plugins/w3-total-cache/DbCache_WpdbInjection_QueryCaching.
   php line 366 with [https://github.com/szepeviktor/fix-w3tc/blob/w3tc-0-9-5/DbCache_WpdbInjection_QueryCaching.php#L366](https://github.com/szepeviktor/fix-w3tc/blob/w3tc-0-9-5/DbCache_WpdbInjection_QueryCaching.php#L366)
   line 366
 *  [manfield75](https://wordpress.org/support/users/manfield75/)
 * (@manfield75)
 * [9 years, 7 months ago](https://wordpress.org/support/topic/undefined-index-http_referer-in-dbcache_wpdbinjection_querycaching-php/#post-8381794)
 * Hello, I’ve the same problem with Wordfence + W3-Total-Cache.
    Actually it happens
   even if you don’t use the plugin panel on a browser. In fact I’ve my log gets
   full in background.
 * The fix Simone proposes does not fix my issue. I guess it is limited to check
   ajax requests.
 * Anyway It gave me the chance to give a look into the w3c-fix fork 😉
 * Thanks
    -  This reply was modified 9 years, 7 months ago by [manfield75](https://wordpress.org/support/users/manfield75/).
 *  [virgodesign](https://wordpress.org/support/users/virgodesign/)
 * (@virgodesign)
 * [9 years, 7 months ago](https://wordpress.org/support/topic/undefined-index-http_referer-in-dbcache_wpdbinjection_querycaching-php/#post-8424357)
 * Same problem here, fixed with [@nigrosimone](https://wordpress.org/support/users/nigrosimone/)
   solution.
    -  This reply was modified 9 years, 7 months ago by [virgodesign](https://wordpress.org/support/users/virgodesign/).

Viewing 3 replies - 1 through 3 (of 3 total)

The topic ‘Undefined index: HTTP_REFERER in DbCache_WpdbInjection_QueryCaching.php’
is closed to new replies.

 * ![](https://ps.w.org/w3-total-cache/assets/icon-256x256.png?rev=1041806)
 * [W3 Total Cache](https://wordpress.org/plugins/w3-total-cache/)
 * [Frequently Asked Questions](https://wordpress.org/plugins/w3-total-cache/#faq)
 * [Support Threads](https://wordpress.org/support/plugin/w3-total-cache/)
 * [Active Topics](https://wordpress.org/support/plugin/w3-total-cache/active/)
 * [Unresolved Topics](https://wordpress.org/support/plugin/w3-total-cache/unresolved/)
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 * 3 replies
 * 4 participants
 * Last reply from: [virgodesign](https://wordpress.org/support/users/virgodesign/)
 * Last activity: [9 years, 7 months ago](https://wordpress.org/support/topic/undefined-index-http_referer-in-dbcache_wpdbinjection_querycaching-php/#post-8424357)
 * Status: not resolved