CVE-2026-65884 in Gridbox Extension
Summary
by MITRE • 07/29/2026
Joomla Extension - balbooa.com - Privilege Escalation in Gridbox < 2.20.2 - The registration method allows users provided usergroup IDs, allowing unauthenticated actors to register new accounts with administrative permissions.
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Analysis
by VulDB Data Team • 07/29/2026
The vulnerability identified in the Joomla extension from balbooa.com affects the Gridbox component version prior to 2.20.2 and represents a critical privilege escalation flaw that directly impacts system security. This issue stems from improper input validation within the registration method, which fails to properly sanitize or restrict usergroup ID parameters provided during account creation. The vulnerability allows unauthenticated attackers to exploit this weakness by submitting malicious usergroup IDs during the registration process, effectively enabling them to create new accounts with administrative privileges without requiring legitimate authentication credentials.
The technical nature of this flaw aligns with common privilege escalation vulnerabilities found in web applications where insufficient access controls and input validation mechanisms exist. The vulnerability specifically demonstrates a lack of proper authorization checks within the user registration flow, allowing attackers to manipulate usergroup assignments during account creation. This type of vulnerability typically falls under CWE-285 which addresses improper authorization issues, and can be categorized as an instance of CVE-2019-19356 based on the specific implementation details.
The operational impact of this privilege escalation vulnerability is severe as it provides attackers with complete administrative control over affected Joomla installations. Once an attacker successfully exploits this vulnerability, they gain unrestricted access to all system resources including but not limited to user management, content modification, plugin configuration, and database access. The attack vector requires no prior authentication credentials, making it particularly dangerous as it can be exploited by anyone with access to the vulnerable web application. This vulnerability directly enables adversaries to establish persistent backdoors, modify critical system configurations, steal sensitive data, or completely compromise the affected Joomla installation.
Mitigation strategies for this vulnerability require immediate action including updating the Gridbox component to version 2.20.2 or later where the registration method properly validates usergroup IDs and implements appropriate authorization checks. System administrators should also implement network-level protections such as firewall rules that restrict access to registration endpoints, deploy web application firewalls to monitor and block suspicious registration attempts, and conduct regular security audits of all installed extensions. Additionally, implementing proper input validation mechanisms at multiple layers including application code, database queries, and API endpoints will help prevent similar issues from occurring in the future.
From an ATT&CK framework perspective, this vulnerability maps directly to technique T1078 which covers valid accounts and privilege escalation through unauthorized access to administrative functions. The exploitation process aligns with T1548.001 which covers abuse of privileges through legitimate account access, while the lack of proper input validation corresponds to T1210 which addresses exploitation of remote services through improper input handling. Organizations should also consider implementing principle of least privilege configurations for user accounts and regularly review user permissions to ensure that administrative access is properly restricted to authorized personnel only. The vulnerability serves as a reminder of the critical importance of validating all user inputs, particularly those used in permission and access control decisions, and demonstrates how seemingly minor implementation flaws can result in complete system compromise.