CVE-2023-46252 in Squidex
Summary
by MITRE • 11/07/2023
Squidex is an open source headless CMS and content management hub. Affected versions are missing origin verification in a postMessage handler which introduces a Cross-Site Scripting (XSS) vulnerability. The editor-sdk.js file defines three different class-like functions, which employ a global message event listener: SquidexSidebar, SquidexWidget, and SquidexFormField. The registered event listener takes some action based on the type of the received message. For example, when the SquidexFormField receives a message with the type valueChanged, the value property is updated. The SquidexFormField class is for example used in the editor-editorjs.html file, which can be accessed via the public wwwroot folder. It uses the onValueChanged method to register a callback function, which passes the value provided from the message event to the editor.render. Passing an attacker-controlled value to this function introduces a Cross-Site Scripting (XSS) vulnerability.
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Analysis
by VulDB Data Team • 12/03/2023
The vulnerability identified as CVE-2023-46252 affects Squidex, an open source headless content management system that serves as a content management hub for digital experiences. This security flaw resides in the message handling mechanisms within the editor-sdk.js file, which implements three distinct class-like functions: SquidexSidebar, SquidexWidget, and SquidexFormField. These components utilize a global message event listener that processes incoming postMessage events without proper origin verification, creating a critical security gap that can be exploited by malicious actors.
The technical implementation of this vulnerability stems from the absence of origin validation in the postMessage handler functionality. When these classes receive messages through the global event listener, they execute actions based on message types such as valueChanged. Specifically, the SquidexFormField class processes these messages by updating its value property, which then gets passed to the editor.render function through the onValueChanged callback mechanism. The editor-editorjs.html file, accessible through the public wwwroot directory, demonstrates how this vulnerability can be exploited by accepting attacker-controlled values directly into the rendering pipeline without proper sanitization or validation.
This cross-site scripting vulnerability occurs because the system fails to validate the source of incoming messages, allowing any origin to send malicious payloads through the postMessage interface. The lack of origin verification creates a pathway for attackers to inject malicious JavaScript code that executes within the context of authenticated users' browsers. The impact extends beyond simple script execution as it enables potential data theft, session hijacking, and privilege escalation attacks against authenticated users who interact with the affected components. The vulnerability is particularly dangerous because it operates within the content management interface where users may have elevated privileges, making it a prime target for exploitation.
The operational impact of this vulnerability is significant for organizations using Squidex, as it can lead to complete compromise of the content management system and potential data breaches. Attackers can leverage this flaw to inject malicious scripts that persist across user sessions and can be triggered when legitimate users access the CMS interface. The vulnerability affects the core functionality of Squidex's editor components, potentially allowing attackers to modify content, steal credentials, or redirect users to malicious sites. Organizations should immediately implement mitigations including origin validation for all postMessage handlers, input sanitization of all message parameters, and network-level restrictions on access to the wwwroot directory.
Security practitioners should reference CWE-79 for the cross-site scripting vulnerability and consider ATT&CK technique T1566 for the initial access vector through malicious content injection. The vulnerability demonstrates poor input validation practices and inadequate security controls around inter-frame communication mechanisms. Organizations should also implement Content Security Policy headers and regularly audit their message handling systems for similar security flaws. The fix requires implementing strict origin verification in all postMessage handlers and ensuring that no user-controllable data flows directly into rendering functions without proper sanitization, aligning with industry best practices for secure web application development and defensive programming principles.