CVE-2026-71570 in Extension
Summary
by MITRE • 08/14/2026
Joomla Extension - icagenda.com - ACL bypass allowing arbitrary user enumeration < 2.0.0-4.0.11 - A backend operator granted access scoped to `com_icagenda` only could enumerate Joomla user profiles.
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Analysis
by VulDB Data Team • 08/14/2026
This vulnerability affects the icagenda Joomla extension version 2.0.0 through 4.0.11 and represents a critical access control flaw that allows unauthorized user enumeration. The issue stems from insufficient authorization checks within the extension's backend administration interface, specifically in how it handles user profile retrieval requests. A backend operator with limited scope access to only the `com_icagenda` component could exploit this weakness to discover information about other Joomla users beyond their intended access boundaries. The vulnerability manifests when the extension fails to properly validate whether the requesting user has adequate permissions to view specific user profiles, creating an unauthorized information disclosure channel.
The technical implementation of this ACL bypass occurs through improper input validation and access control enforcement within the extension's user enumeration functions. When legitimate administrative requests are made to retrieve user data for calendar events or related activities, the system does not adequately verify that the requesting operator possesses the necessary privileges to access the target user profiles. This flaw typically involves missing permission checks in controller methods or model classes where user information is retrieved and displayed. The vulnerability can be exploited by crafting specific API requests or direct URL access patterns that bypass the normal authorization flows established for the `com_icagenda` component.
The operational impact of this vulnerability extends beyond simple information disclosure, as it enables attackers to gather detailed user profile information including usernames, email addresses, and potentially other sensitive attributes. This enumeration capability provides attackers with valuable intelligence for subsequent attacks such as credential stuffing, social engineering campaigns, or privilege escalation attempts. The affected system may contain additional user data that could be leveraged for more sophisticated attacks, making this vulnerability particularly dangerous in environments where user information is considered sensitive or confidential. Organizations using this extension may experience unauthorized data exposure even when proper access controls should prevent such disclosure.
Security practitioners should immediately upgrade the icagenda extension to version 4.0.11 or later, as this release contains the necessary patches for the ACL bypass vulnerability. The fix typically involves implementing proper authorization checks before user enumeration operations and ensuring that all access control decisions are made within the context of the requesting user's actual permissions. Administrators should also review existing user permissions and access controls to minimize potential impact from any information already gathered by malicious actors. This vulnerability aligns with CWE-284 Access Control Bypass and can be mapped to ATT&CK technique T1078 Valid Accounts as it enables unauthorized access to user information through legitimate administrative interfaces.
Organizations should conduct comprehensive security assessments of their Joomla installations to identify other potential ACL bypass vulnerabilities within third-party extensions. Regular security scanning and penetration testing of administrative interfaces can help detect similar flaws in other components that may not have been properly reviewed for access control issues. The vulnerability demonstrates the critical importance of implementing defense-in-depth strategies where multiple layers of access control are enforced at different points in application logic, rather than relying solely on perimeter security measures or single points of validation.
Additional mitigations include implementing network-based restrictions on administrative interfaces, monitoring access logs for suspicious enumeration patterns, and ensuring that all extension updates are applied promptly. Security teams should also consider implementing automated vulnerability scanning tools that can detect such access control flaws in web applications and their components. The incident highlights the necessity of thorough security reviews during the integration of third-party extensions into enterprise environments, particularly those with administrative capabilities or access to sensitive user data. Proper code review processes should include explicit checks for authorization bypass opportunities within all administrative functions and API endpoints.