By Glenn Ansley  |  October 20th, 2009

There have been several reports this morning of a DOS attack affecting the WordPress wp-trackback.php file.

[original post] http://www.stevefortuna.com/new-0-day-wordpress-exploit/
All the the solutions have been the same thus far and require editing your .htaccess file or the wp-trackback.php file.

FullThrottle has composed this quick plugin that accomplishes the same thing as the edit to the wp-trackback.php file. You may download the plugin below or paste the following code into your theme’s functions.php file.

We will update this post and our code if further insight into the attack deems it necessary.

function ft_stop_trackback_dos_attacks(){
global $pagenow;
if ( ‘wp-trackback.php’ == $pagenow ){
// DoS attack fix.
if ( isset($_POST[‘charset’]) ){
$charset = $_POST[‘charset’];
if ( strlen($charset) > 50 ) { die; }
Download the plugin here: ft-stop-trackback-dos-attacks.php


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Steve Fortuna says:
October 20th, 2009 at 6:12 am (#)

Thanks for this plugin. Will help a lot of people fix this who aren’t familiar with working in code.

Also, I would like to let you know that the post on http://jarraltech.com is an exact copy of mine. He plagiarized it from my blog.

He didn’t try to hide the timestamps either, so it’s very apparent.

Jared Atchison » Blog Archive » WordPress trackback exploit found says:
October 20th, 2009 at 12:35 pm (#)

[…] is a chunk of code you can paste into your theme’s functions.php […]

D Mang says:
October 20th, 2009 at 4:47 pm (#)

Mega props!

The GFY community thanks you..

Sicherheitslücke bei WordPress ermöglichst Trackback-DoS-Attacken | Webseiten-Infos.de says:
October 20th, 2009 at 4:59 pm (#)

[…] WordPress Plugin to Stop Trackback DOS attacks bei fullthrottledevelopment.com […]

WordPress Trackback Sicherheitslücke | elexpress.de says:
October 20th, 2009 at 6:39 pm (#)

[…] da ich es noch nicht testen konnte. Das entsprechende Exploit ist bereits im Umlauf und ein Plugin, welches die Lücke vorerst schließen soll, gibt es bereits. Jedoch habe ich bei dem Plugin […]

WordPress Trackback DOS Aattacks | Lannen Designs says:
October 20th, 2009 at 7:36 pm (#)

[…] how this needs to be fixed ASAP on WordPress install. You can download a plug-in to fix this right here. I would highly recommend […]

CGHill says:
October 20th, 2009 at 7:55 pm (#)

Good enough. I figure they’ll shovel it out to us in the morning. (I have four blogs to do.)

CGHill says:
October 20th, 2009 at 9:46 pm (#)

Very nice. Should this plugin be deactivated before installing 2.8.5?

Glenn says:
October 20th, 2009 at 9:59 pm (#)

@CGHill: The plugin is not needed once you update to 2.8.5 so you might as well deactivate it. In the event that you leave it activated though, there shouldn’t be any conflicts.

WordPress Upgrade 2.8.5 | Mena Studios LLC says:
October 20th, 2009 at 11:44 pm (#)

[…] is some more info about the exploit. /wordpress-plugin-to-stop-trackback-dos-attacks AKPC_IDS += “344,”; Share and […]

Gros says:
October 20th, 2009 at 11:54 pm (#)

I think something like this is more pretty: 😉

if ( ($charset) && strtoupper( trim($charset))=== get_option(’blog_charset’);

$charset = get_option(’blog_charset’);//$charset = strtoupper( trim($charset));


$charset = ‘ASCII, UTF-8, ISO-8859-1, JIS, EUC-JP, SJIS’;

Harsh Agrawal says:
October 22nd, 2009 at 3:24 am (#)

Saw this update Yesterday and the first thing which I did

was Backup my Db and updated the wordpress. Though wordpress are releasing very quick update.. 😐