WordPress quickly patches second critical vulnerability

It's the second time in a week WordPress had fixed flaws involving malicious comments

WordPress patched a second critical vulnerability in its Web publishing platform on Monday, less than a week after fixing a similar problem.

Administrators are advised to upgrade to WordPress version 4.2.1. Some WordPress sites that are compatible with and use a plugin called Background Update Tester will update automatically.

WordPress is one of the most-used Web publishing platforms. By the company's own estimation, it runs 23 percent of the sites on the Internet, including major publishers such as Time and CNN.

The latest flaw was found by Jouko Pynnönen[cq] of Klikki Oy, a Finish software company. Pynnönen found WordPress was vulnerable to a cross-site scripting flaw if an attacker inserted malicious JavaScript into a comments field. The script runs when someone views the comment, according to an advisory.

Cross-site scripting flaws are among the most dangerous and common Web vulnerabilities, allowing rogue code to run that should be forbidden.

If a WordPress administrator is logged in when the malicious comment is viewed, the attacker can then execute arbitrary code on the server through the plugin and theme editors. It is also then possible to change the administrator's password, create new administrator accounts or manipulate content on a site. The vulnerability can't cause damage from an ordinary reader viewing the comment.

Klikki Oy alleged that WordPress had stopped communicating with it last November when Klikki found a different vulnerability in WordPress. With the latest flaw, Klikki said it had also tried to notify WordPress through the Finnish computer security authority, CERT-FI, and HackerOne, which offers a service for managing vulnerability reports and rewards.

On April 21, WordPress patched a vulnerability similar to the one Pynnönen came across. Cedric Van Bockhaven[cq] found that WordPress was vulnerable to a cross-site scripting attack involving comments due to a MySQL database behavior it allowed.

He found that rogue code could be executed when a person hovered over a malicious script inserted into a comments field. Proof-of-concept code written by Van Bockhaven showed how a new user could be added in the administration panel. The flaw could also be used to download a plugin that runs malicious server-side code, he wrote on his blog.

Send news tips and comments to jeremy_kirk@idg.com. Follow me on Twitter: @jeremy_kirk

Join the Good Gear Guide newsletter!

Error: Please check your email address.

Tags securityWordpressExploits / vulnerabilitiesKlikki Oy

Our Back to Business guide highlights the best products for you to boost your productivity at home, on the road, at the office, or in the classroom.

Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Jeremy Kirk

IDG News Service
Show Comments

Essentials

Lexar® JumpDrive® S57 USB 3.0 flash drive

Learn more >

Microsoft L5V-00027 Sculpt Ergonomic Keyboard Desktop

Learn more >

Mobile

Lexar® JumpDrive® S45 USB 3.0 flash drive 

Learn more >

Exec

Audio-Technica ATH-ANC70 Noise Cancelling Headphones

Learn more >

HD Pan/Tilt Wi-Fi Camera with Night Vision NC450

Learn more >

Lexar® JumpDrive® C20c USB Type-C flash drive 

Learn more >

Lexar® Professional 1800x microSDHC™/microSDXC™ UHS-II cards 

Learn more >

Budget

Back To Business Guide

Click for more ›

Most Popular Reviews

Latest News Articles

Resources

PCW Evaluation Team

Azadeh Williams

HP OfficeJet Pro 8730

A smarter way to print for busy small business owners, combining speedy printing with scanning and copying, making it easier to produce high quality documents and images at a touch of a button.

Andrew Grant

HP OfficeJet Pro 8730

I've had a multifunction printer in the office going on 10 years now. It was a neat bit of kit back in the day -- print, copy, scan, fax -- when printing over WiFi felt a bit like magic. It’s seen better days though and an upgrade’s well overdue. This HP OfficeJet Pro 8730 looks like it ticks all the same boxes: print, copy, scan, and fax. (Really? Does anyone fax anything any more? I guess it's good to know the facility’s there, just in case.) Printing over WiFi is more-or- less standard these days.

Ed Dawson

HP OfficeJet Pro 8730

As a freelance writer who is always on the go, I like my technology to be both efficient and effective so I can do my job well. The HP OfficeJet Pro 8730 Inkjet Printer ticks all the boxes in terms of form factor, performance and user interface.

Michael Hargreaves

Windows 10 for Business / Dell XPS 13

I’d happily recommend this touchscreen laptop and Windows 10 as a great way to get serious work done at a desk or on the road.

Aysha Strobbe

Windows 10 / HP Spectre x360

Ultimately, I think the Windows 10 environment is excellent for me as it caters for so many different uses. The inclusion of the Xbox app is also great for when you need some downtime too!

Mark Escubio

Windows 10 / Lenovo Yoga 910

For me, the Xbox Play Anywhere is a great new feature as it allows you to play your current Xbox games with higher resolutions and better graphics without forking out extra cash for another copy. Although available titles are still scarce, but I’m sure it will grow in time.

Featured Content

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?