Recent WordPress vulnerability used to deface 1.5 million pages

Attackers are exploiting the recently patched REST API vulnerability that allows code to be injected into WordPress websites

Up to 20 attackers or groups of attackers are defacing WordPress websites that haven't yet applied a recent patch for a critical vulnerability.

The vulnerability, located in the platform's REST API, allows unauthenticated attackers to modify the content of any post or page within a WordPress site. The flaw was fixed in WordPress 4.7.2, released on Jan. 26, but the WordPress team did not publicly disclose the vulnerability's existence until a week later, to allow enough time for a large number of users to deploy the update.

However, even after the flaw became public, many webmasters did not apply the patch and a wave of attacks soon followed. On Monday, web security firm Sucuri reported that around 67,000 pages had been defaced in four separate attack campaigns.

Since then the number of defaced pages has grown to over 1.5 million and there are 20 different attack signatures, according to statistics from Feedjit, the company behind the Wordfence security plug-in for WordPress. The number of unique affected websites is estimated at around 40,000, as a site can have multiple defaced pages.

"This vulnerability has resulted in a kind of feeding frenzy where attackers are competing with each other to deface vulnerable WordPress websites," Mark Maunder, the CEO of Feedjit, said in a blog post Thursday. "During the past 48 hours we have seen over 800,000 attacks exploiting this specific vulnerability across the WordPress sites we monitor."

One interesting aspect is that attackers have managed to find a way to defeat the initial blocking rules put in place by web application firewall vendors and web hosting companies to protect their customers from attempts to exploit this flaw.

These companies can't force webmasters to update their WordPress installations, but they can put filters in place on their web servers to block such attacks from reaching their customers' websites. In fact, before releasing the official patch, the WordPress security team reached out to select web security and hosting firms to help them deploy protection rules for this flaw.

Google has also sent out security alerts regarding this vulnerability to webmasters who registered their WordPress websites in the Google Search Console service. The alerts advised them to install the WordPress 4.7.2 update but generated some confusion among users who had already applied the patch.

The truth is that despite these efforts, some WordPress installations won't be updated and will remain vulnerable to this flaw for a long time to come. This is based on past experience with other serious flaws that affected WordPress and similar content management solutions. 

The bad news is that it's probably only a matter of time until attackers stop defacing pages and start injecting malicious code into them, affecting their visitors.

Join the newsletter!

Error: Please check your email address.
Rocket to Success - Your 10 Tips for Smarter ERP System Selection
Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Lucian Constantin

IDG News Service
Show Comments

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

Sarah Ieroianni

Brother QL-820NWB Professional Label Printer

The print quality also does not disappoint, it’s clear, bold, doesn’t smudge and the text is perfectly sized.

Ratchada Dunn

Sharp PN-40TC1 Huddle Board

The Huddle Board’s built in program; Sharp Touch Viewing software allows us to easily manipulate and edit our documents (jpegs and PDFs) all at the same time on the dashboard.

George Khoury

Sharp PN-40TC1 Huddle Board

The biggest perks for me would be that it comes with easy to use and comprehensive programs that make the collaboration process a whole lot more intuitive and organic

David Coyle

Brother PocketJet PJ-773 A4 Portable Thermal Printer

I rate the printer as a 5 out of 5 stars as it has been able to fit seamlessly into my busy and mobile lifestyle.

Kurt Hegetschweiler

Brother PocketJet PJ-773 A4 Portable Thermal Printer

It’s perfect for mobile workers. Just take it out — it’s small enough to sit anywhere — turn it on, load a sheet of paper, and start printing.

Matthew Stivala

HP OfficeJet 250 Mobile Printer

The HP OfficeJet 250 Mobile Printer is a great device that fits perfectly into my fast paced and mobile lifestyle. My first impression of the printer itself was how incredibly compact and sleek the device was.

Featured Content

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?