Critical security vulnerability in Grails could lead to remote code execution

Maintainers warn to patch all versions of open source web app framework – even those not deemed vulnerable

Researchers from AntGroup FG Security Lab have discovered a critical security vulnerability allowing an attacker to remotely execute code within a Grails application runtime.

Grails is an open source web application framework based on the Apache Groovy programming language and is used for developing agile web applications. Customers include Google, IBM, Walmart, Credit Suisse, and Mastercard.

The flaw, tracked using CVE-2022-35912, allows an attacker to remotely execute code within a Grails application runtime by issuing a specially crafted web request that grants the attacker access to the class loader.

The attack exploits a section of the Grails data-binding logic, which is invoked in a number of ways including the creation of command objects, domain class construction, and manual data binding when using bindData.

The vulnerability has been confirmed on Grails framework versions 3.3.10 and higher, including Grails framework 4 and 5, that are running on Java 8. It has been observed in both the embedded Tomcat runtime and applications deployed as a Web Archive (WAR) to a Tomcat instance.

“Due to the nature of this vulnerability, we strongly suggest that all Grails applications, including those that are not vulnerable to this specific attack, be updated to a patched Grails release,” the Grails team noted in a blog post.

“While we have not been able to reproduce this specific exploit on applications running in Java 11 or in versions of the Grails framework before 3.3.10, the nature of the vulnerability is such that variations on the attack could be discovered that earlier Grails releases, and Grails applications running on higher versions of Java will be impacted.”

Patches available

Versions 5.2.1, 5.1.9, 4.1.1, and 3.3.15 have now been patched, and the team recommends upgrading to a patched version. Grails 4.x applications can be upgraded to version 4.1.1 or higher, Grails 5.0.x and 5.1.x applications can be upgraded to 5.1.9 or higher, and Grails 5.2 applications can be upgraded to 5.2.1 or higher.

“The Grails Foundation and the Grails core development team take application security very seriously,” wrote the team. “We are continuing to research and monitor this vulnerability.”