CVE-2026-101093 in Cotonti
Summary
by MITRE • 09/29/2026
Cotonti through 1.0.0 contains a cross-site request forgery vulnerability in admin.users.php that allows attackers to delete user groups without token verification. Attackers can craft malicious links or pages that trick authenticated administrators into deleting custom groups and their associated permissions by riding the administrator's session.
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Analysis
by VulDB Data Team • 09/29/2026
The identified vulnerability represents a critical Cross-Site Request Forgery (CSRF) flaw within the administrative interface of Cotonti, specifically affecting versions up to 1.0.0. This security deficiency is located in the admin.users.php module and centers on the user group management functionality. The core technical issue stems from the absence of anti-CSRF token verification mechanisms for state-changing HTTP requests that modify or delete user groups. In a properly secured web application, any action that alters server-side data must require proof that the request originated from an authenticated session initiated by the legitimate user. However, in this instance, the system relies solely on standard browser cookie-based authentication without implementing additional safeguards such as synchronizer tokens or double-submit cookies to validate the intent of the requester.
From a technical perspective, the vulnerability allows remote attackers to craft malicious web pages or links containing forged HTTP requests targeting the vulnerable endpoint. When an authenticated administrator with sufficient privileges visits this malicious page or clicks the crafted link while their session is still active in the browser, the browser automatically attaches the relevant authentication cookies to the request due to same-origin policy exceptions for cross-site scripting contexts involving forms or image tags. The server processes this request as legitimate because it contains valid credentials but fails to verify that the administrator explicitly intended to perform the deletion action via a trusted interface. This lack of origin validation and state change protection enables an attacker to execute unauthorized administrative actions on behalf of the victim without their knowledge or consent.
The operational impact of this vulnerability is severe, particularly in environments where Cotonti serves as a content management system with multiple administrators managing distinct user roles and permissions. An successful exploitation allows attackers to delete custom user groups entirely. Since these groups often contain specific permission sets that define what actions different users can perform within the application, their removal can lead to significant disruption of access control policies. This may result in unintended privilege escalation if default or less restricted groups become the primary method for certain operations, or it could cause a denial of service by breaking workflows dependent on those specific group structures. Furthermore, the ability to manipulate user permissions undermines the integrity of the administrative model and can facilitate further attacks such as unauthorized data access or system compromise.
This vulnerability aligns with CWE-352, which describes Cross-Site Request Forgery, indicating a failure in validating that state-changing requests are authorized by the current user. In terms of offensive security frameworks, this exploit technique maps to MITRE ATT&CK Tactic TA0001 (Initial Access) and specifically Technique T1078 (Valid Accounts), as it leverages existing valid credentials through social engineering or malicious web content rather than exploiting a software bug in the authentication logic itself. It also relates to Defense Evasion techniques where attackers manipulate trusted sessions to bypass intended security controls.
To mitigate this vulnerability, immediate remediation should focus on implementing robust anti-CSRF measures within the admin.users.php module and other state-changing endpoints across the Cotonti platform. This includes generating unique, unpredictable synchronization tokens for each user session that must be included in all POST requests modifying data. The server must validate these tokens before processing any deletion or modification request. Additionally, developers should ensure that sensitive actions require re-authentication or explicit confirmation dialogs to prevent silent execution of destructive commands. Upgrading to a patched version of Cotonti where this flaw has been addressed is the most effective long-term solution for organizations relying on this software infrastructure.