Connect with us

Hi, what are you looking for?

SecurityWeekSecurityWeek

Vulnerabilities

Official Fix for PHP Flaw Easily Bypassed, Researchers Say

On Wednesday, a remote code execution vulnerability in PHP was accidentally exposed to the Web, prompting fears that it may be used to target vulnerable websites on a massive scale. The bug itself was traced back to 2004, and came to light during a recent CTF competition.

The group that discovered the bug was waiting for a patch to be published before they released any information. However, on Wednesday details were leaked to Reddit prompting the group (Eindbazen) disclose what they had discovered.

On Wednesday, a remote code execution vulnerability in PHP was accidentally exposed to the Web, prompting fears that it may be used to target vulnerable websites on a massive scale. The bug itself was traced back to 2004, and came to light during a recent CTF competition.

The group that discovered the bug was waiting for a patch to be published before they released any information. However, on Wednesday details were leaked to Reddit prompting the group (Eindbazen) disclose what they had discovered.

[Update: On May 08, the PHP development team released PHP 5.4.3 and PHP 5.3.13. All users are encouraged to upgrade to PHP 5.4.3 or PHP 5.3.13.]

“When PHP is used in a CGI-based setup (such as Apache’s mod_cgid), the php-cgi receives a processed query string parameter as command line arguments which allows command-line switches, such as -s, -d or -c to be passed to the php-cgi binary, which can be exploited to disclose source code and obtain arbitrary code execution,” a CERT advisory on the flaw explains.

In short, the flaw will attackers to issue commands to servers where PHP has been compiled to run under CGI mode. This is often done for security and development reasons. It’s important to note that FastCGI configurations are not impacted by the flaw.

PHP developers pushed a fix for the flaw, resulting in the release of PHP 5.3.12 and 5.4.2, but as it turns out it didn’t actually remove the vulnerability.

“The new PHP versions as well as the official PHP patch contain a bug which makes the fix trivial to bypass. Use our mitigations for now,” the Eindbazen team wrote on their blog.

Mitigations as well as additional information from Eindbazen can be found on their website. You can view it here

Advertisement. Scroll to continue reading.

Finally, the developers over at PHP are aware of the issues created by the fix and are working to stamp out the problem.

Interested in Secure Development Strategies? Join us for a live Webinar on May 23 at 1:00PM: “The Great Security Divide: How security can work better with development“, presented by Coverity Founder and CTO, Andy Chou. You can register free here.

Written By

Click to comment

Trending

Daily Briefing Newsletter

Subscribe to the SecurityWeek Email Briefing to stay informed on the latest threats, trends, and technology, along with insightful columns from industry experts.

Learn about active threats targeting common cloud deployments and what security teams can do to mitigate them.

Register

Join us for an in depth exploration of the critical nature of software and vendor supply chain security issues with a focus on understanding how attacks against identity infrastructure come with major cascading effects.

Register

Expert Insights

Related Content

Vulnerabilities

Less than a week after announcing that it would suspended service indefinitely due to a conflict with an (at the time) unnamed security researcher...

Data Breaches

OpenAI has confirmed a ChatGPT data breach on the same day a security firm reported seeing the use of a component affected by an...

IoT Security

A group of seven security researchers have discovered numerous vulnerabilities in vehicles from 16 car makers, including bugs that allowed them to control car...

Vulnerabilities

A researcher at IOActive discovered that home security systems from SimpliSafe are plagued by a vulnerability that allows tech savvy burglars to remotely disable...

Risk Management

The supply chain threat is directly linked to attack surface management, but the supply chain must be known and understood before it can be...

Cybercrime

Patch Tuesday: Microsoft calls attention to a series of zero-day remote code execution attacks hitting its Office productivity suite.

Vulnerabilities

Patch Tuesday: Microsoft warns vulnerability (CVE-2023-23397) could lead to exploitation before an email is viewed in the Preview Pane.

Vulnerabilities

The latest Chrome update brings patches for eight vulnerabilities, including seven reported by external researchers.