PHP 5.3.10 fixes critical remote code execution vulnerability

The vulnerability was introduced by the fix for a hash collision denial-of-service flaw

The PHP Group released PHP 5.3.10 on Thursday in order to address a critical security flaw that can be exploited to execute arbitrary code on servers running an older version of the Web development platform.

The vulnerability is identified as CVE-2012-0830 and was discovered by Stefan Esser, an independent security consultant and creator of the popular Suhosin security extension for PHP.

SecurityFocus classifies the issue as a design error because it was accidentally introduced while fixing a separate denial-of-service (DoS) vulnerability in early January.

That vulnerability is known as CVE-2011-4885 and was disclosed in December 2011 at the Chaos Communication Congress by security researchers Alexander Klink and Julian Wälde.

It affects a number of Web development platforms including PHP, ASP.NET, Java and Python and can be exploited in a so-called hash collision attack. The PHP development team addressed CVE-2011-4885 in PHP 5.3.9, which was released on Jan. 10.

"The fix for the Hash Collision DoS introduced a new directive (max_input_vars) to limit the number of accepted input variables," said Carsten Eiram, chief security specialist at vulnerability research firm Secunia.

"However, due to a logic error in the "php_register_variable_ex()" function in php_variables.c certain cases are not handled correctly when the number of supplied variables is greater than the imposed limit," he explained.

This error can be exploited by attackers to remotely execute arbitrary code on a system that runs a vulnerable PHP installation. PHP 5.3.9 along with any older versions for which the hash collision DoS patch was backported, are affected, Eiram said.

Proof-of-concept code that exploits this vulnerability has already been published online, so the likelihood of attacks targeting CVE-2012-0830 are high. Web servers administrators are advised to upgrade to PHP 5.3.10 immediately.

Join the PC World 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

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.

Armand Abogado

HP OfficeJet 250 Mobile Printer

Wireless printing from my iPhone was also a handy feature, the whole experience was quick and seamless with no setup requirements - accessed through the default iOS printing menu options.

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.

Featured Content

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?