CVE-2026-102784 in Gridbox Extension
Summary
by MITRE • 10/08/2026
Joomla Extension - balbooa.com - CSRF in language installation feature Gridbox < 2.20.4.0 - PagesController uses a trait that validates the Joomla session token only when the HTTP method is POST. addLanguage does not require POST inside the action and reads url and zip through the generic request input. A GET request can therefore reach the action without the trait checking a token. The action still requires core.tools , but that is the victim’s permission check; it does not prove that the privileged user intended the request.
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Analysis
by VulDB Data Team • 10/08/2026
The vulnerability identified in Gridbox versions prior to 2.20.4.0 represents a critical Cross-Site Request Forgery (CSRF) flaw within the Joomla extension's language installation functionality. This issue stems from an inconsistent implementation of session token validation mechanisms, specifically affecting the PagesController class which utilizes a trait designed to enforce security checks on incoming requests. The core technical failure lies in the conditional logic governing this trait; it is configured to validate the Joomla session token exclusively when the HTTP method associated with the request is POST. However, the specific action responsible for adding languages, known as addLanguage, does not strictly mandate the use of the POST method. Instead, it retrieves necessary parameters such as the URL and zip file path through a generic request input handler that accepts data from various HTTP methods including GET.
This architectural oversight allows an attacker to craft malicious requests using standard GET URLs rather than requiring complex form submissions or POST payloads. Because the session token validation is bypassed for non-POST requests, an authenticated administrator can be tricked into executing unintended actions simply by visiting a crafted link hosted on a malicious website. The vulnerability exploits the fact that while the application does check for core.tools permissions to ensure the user has administrative privileges, this permission check only verifies identity and authorization level rather than intent. It fails to confirm that the privileged user explicitly initiated the request through their own interface, thereby leaving the system vulnerable to coercion by third-party sites.
From an operational impact perspective, successful exploitation of this vulnerability allows attackers to install arbitrary language packs into the Joomla installation without explicit consent from the administrator. This can lead to a range of severe consequences including defacement of the website, injection of malicious code through compromised language files, or complete compromise of the underlying server if the uploaded package contains executable scripts that exploit other system vulnerabilities. The ease of exploitation via simple GET requests significantly lowers the barrier for entry, making this vulnerability particularly dangerous in environments where administrators frequently click on links received via email or social media without verifying their source integrity.
To mitigate this risk, immediate updates to Gridbox version 2.20.4.0 or later are required as these versions address the inconsistent token validation logic. In the interim, site administrators should implement strict Content Security Policy headers and utilize CSRF protection plugins that enforce token verification across all HTTP methods regardless of their type. Additionally, restricting file upload permissions and monitoring for unauthorized language pack installations can help detect potential exploitation attempts early. This vulnerability aligns with CWE-352 Cross-Site Request Forgery due to the lack of anti-CSRF tokens in state-changing operations and maps to ATT&CK technique T1078 Valid Accounts as it relies on hijacking legitimate administrative credentials through social engineering or malicious links.