CVE-2026-93873 in Cotonti
Summary
by MITRE • 09/18/2026
Cotonti through 1.0.0 fails to validate anti-CSRF tokens in the contact plugin submission handler, allowing attackers to forge messages. Attackers can auto-submit contact forms from attacker-controlled pages to send forged messages attributed to authenticated victims to the administrator inbox.
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Analysis
by VulDB Data Team • 09/18/2026
The vulnerability identified in Cotonti versions through 1.0.0 represents a critical failure in cross-site request forgery defenses within its contact plugin submission handler. This flaw stems directly from an absence of proper anti-CSRF token validation, which is a fundamental security control designed to ensure that state-changing requests are initiated by the legitimate user who intended them. In this specific implementation, the server-side logic processes form submissions without verifying the presence or validity of a unique, unpredictable token tied to the user's session. This omission allows an attacker to craft malicious HTTP POST requests that mimic legitimate administrative actions, effectively bypassing the application's authentication and authorization checks for CSRF protection mechanisms.
From a technical perspective, this flaw aligns with CWE-352, which classifies Cross-Site Request Forgery as a weakness where a web application uses GET or POST requests to perform state-changing functions without adequately verifying that the request was intentionally made by the user who is authenticated. The operational impact of this vulnerability is significant because it enables attackers to auto-submit contact forms from pages under their control. By embedding malicious JavaScript in a website visited by an authenticated victim, typically via phishing or drive-by download techniques, the attacker can trigger these forged submissions without any further interaction from the victim. Consequently, messages are sent directly to the administrator inbox but appear to originate from the compromised user account.
This capability allows for sophisticated social engineering attacks where attackers impersonate legitimate users to send deceptive emails to system administrators. These forged messages could contain malicious links, phishing content, or instructions designed to trick administrators into performing unintended actions such as granting elevated privileges, resetting passwords, or executing arbitrary code if other vulnerabilities exist in the administrative interface. The trust relationship between the user and the application is exploited because the server assumes that any request containing valid session cookies was authorized by the owner of those credentials. This undermines the integrity of communication channels within the CMS and can lead to further compromise of the underlying infrastructure.
To mitigate this vulnerability, developers must implement robust anti-CSRF measures across all state-changing endpoints in Cotonti. The standard industry practice involves generating a unique, cryptographically secure random token for each user session upon login or page load. This token must then be embedded as a hidden field within HTML forms and validated on the server side during submission. If the submitted token does not match the one stored in the session, the request should be rejected immediately. Additionally, implementing the SameSite attribute for cookies can provide an additional layer of defense by restricting how browsers send cookies with cross-site requests. Regular security audits and code reviews focusing on input validation and state management are essential to prevent similar flaws from being introduced in future updates or custom plugins within the Cotonti ecosystem.