Drupal sites at risk due to insecure update mechanism

The updates are done over unencrypted connections, so are potentially vulnerable to hijacking

The update mechanism of the popular Drupal content management system is insecure in several ways, allowing attackers to trick administrators into installing malicious updates.

Researcher Fernando Arnaboldi from security firm IOActive noticed that Drupal will not inform administrators that an update check has failed, for example due to inability to access the update server. Instead, the back-end panel will continue to report that the CMS is up to date, even if it's not.

This can be a problem, considering that hackers are quick to exploit vulnerabilities in popular content management systems like Drupal, WordPress or Joomla, after they appear. In one case in 2014, users had only a seven-hour window to deploy a critical Drupal patch until attackers started exploiting the vulnerability that it fixed.

After investigating further, Arnaboldi found that the Drupal updates are not performed over HTTPS, which means that the connections are not encrypted and can potentially be hijacked by man-in-the-middle attackers.

The CMS first downloads an XML file from the updates.drupal.org server and checks to see if the version inside it matches the one installed. If the XML file lists a newer version, the CMS will display an alert in the administration panel that an update is available. It will also provide a download link for the new version, which is also obtained from the XML file.

This means that if an attacker is in a position to intercept network traffic between the Drupal website and the Drupal update server, he can serve a rogue XML file with a link pointing to a backdoored version of the CMS, Arnaboldi explained.

Updating Drupal itself is a manual process, so the attacker would have to wait for the administrator to manually download the rogue update and install it.

However, updating individual Drupal modules -- extensions to the CMS -- is semi-automatic. The administrator only needs to click the download button for a module update and it will be installed automatically.

The process for module updates is also unprotected and can be similarly hijacked. A rogue module update can give the attacker the ability to execute code on the Web server or to access the site's database, according to Arnaboldi.

A third issue is with the link that allows administrators to manually check for updates, which is vulnerable to cross-site request forgery attacks. This means that if an administrator visits an attacker-controlled website, that website can silently force his browser to trigger repeated update checks for the Drupal installation that he's logged into.

This is a form of session hijacking and the attack can force the affected website to consume network bandwidth by repeatedly requesting information from updates.drupal.org.

These issues are not yet fixed, so Drupal administrators might want to manually download all updates for Drupal and its modules themselves for the moment, Arnaboldi said in a blog post.

Join the Good Gear Guide newsletter!

Error: Please check your email address.

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.

Lucian Constantin

IDG News Service
Show Comments

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?