Hackers exploit vBulletin vulnerability to inject rogue administrator accounts

Users should delete the 'install' directories from their vBulletin deployments and upgrade to the latest version of the software

Hackers are exploiting a vulnerability in the popular vBulletin Internet forum software in order to inject rogue administrator accounts into websites using it.

The exploit was found by researchers from security firm Imperva on underground hacker forums and targets versions 4.x.x and 5.x.x of vBulletin.

At the end of August, vBulletin Solutions, the company that develops the forum software, advised users to delete the "install" directories from their vBulletin deployments because of an unspecified exploit vector.

The company declined to release any additional information about the issue at that time, but Imperva's researchers believe it's the same vulnerability targeted by the exploit script they found.

The vulnerability allows attackers to abuse the vBulletin configuration mechanism to create a secondary administrative account, the researchers said Wednesday in a blog post.

In order to exploit the vulnerability, attackers need to know the exact URL for the upgrade.php script from the install directories of the targeted vBulletin deployments and the vBulletin customer IDs associated with those deployments.

To obtain this information, hackers created a separate PHP script that scans vBulletin sites for the vulnerable path and extracts the customer IDs from the source code of the upgrade.php pages, the researchers said.

Once they have those details, attackers only need to choose a username and password for the rogue administrator account that will be created and the exploit will do the rest.

VBulletin Solutions declined to confirm whether the exploit identified by Imperva is the one they warned about in August.

"We've released updates to vBulletin 4 and vBulletin 5," said Wayne Luke, technical support lead at vBulletin Solutions, Wednesday via email. "These are vBulletin 4.2.2 and vBulletin 5.0.5. We recommend customers delete their install directories when not in use maintaining their software."

"I cannot provide any further information on the issue," Luke said.

Notes accompanying the exploit script found by Imperva claim the vulnerability was discovered on Aug. 22.

The Imperva researchers have seen traffic from an attack that successfully exploited a forum powered by vBulletin 4.2.0 and there are also reports about successful attacks against others using version 4.2.1, said Tal Be'ery, security research team leader at Imperva, Thursday via email. However, the company hasn't tested whether the latest 4.2.2 and 5.0.5 versions are vulnerable to the exploit, he said.

The directories that vBulletin users should delete in order to protect their deployments are "/install" for vBulletin 4.1.x versions and "/core/install" for the 5.x versions.

Users who, for some reason, are unable to delete these directories, can use the Web server access configuration mechanism or a Web application firewall to block requests or redirects for upgrade.php, the Imperva researchers said.

The vBulletin software powers over 100,000 Internet community forums, including some very large ones. UbuntuForums.org, a community website for Ubuntu Linux with more than 1.8 million registered accounts that was compromised by hackers in July, is also using vBulletin.

Join the newsletter!

Error: Please check your email address.
Rocket to Success - Your 10 Tips for Smarter ERP System Selection

Tags securitysoftwareImpervapatchesAccess control and authenticationExploits / vulnerabilitiesvBulletin Solutions

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

Cool Tech

SanDisk MicroSDXC™ for Nintendo® Switch™

Learn more >

Breitling Superocean Heritage Chronographe 44

Learn more >

Toys for Boys

Family Friendly

Panasonic 4K UHD Blu-Ray Player and Full HD Recorder with Netflix - UBT1GL-K

Learn more >

Stocking Stuffer

Razer DeathAdder Expert Ergonomic Gaming Mouse

Learn more >

Christmas Gift Guide

Click for more ›

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

Edwina Hargreaves

WD My Cloud Home

I would recommend this device for families and small businesses who want one safe place to store all their important digital content and a way to easily share it with friends, family, business partners, or customers.

Walid Mikhael

Brother QL-820NWB Professional Label Printer

It’s easy to set up, it’s compact and quiet when printing and to top if off, the print quality is excellent. This is hands down the best printer I’ve used for printing labels.

Ben Ramsden

Sharp PN-40TC1 Huddle Board

Brainstorming, innovation, problem solving, and negotiation have all become much more productive and valuable if people can easily collaborate in real time with minimal friction.

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

Featured Content

Product Launch Showcase

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?