CVE-2021-28162 in Theia
Summary
by MITRE • 03/13/2021
In Eclipse Theia versions up to and including 0.16.0, in the notification messages there is no HTML escaping, so Javascript code can run.
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Analysis
by VulDB Data Team • 04/01/2021
The vulnerability identified as CVE-2021-28162 affects Eclipse Theia versions up to and including 0.16.0, specifically within the notification message handling mechanism. This represents a critical security flaw that stems from insufficient input validation and sanitization in the user interface components responsible for displaying system notifications. The issue manifests when the application processes notification messages that contain user-provided content without proper HTML escaping mechanisms, creating a potential vector for malicious code execution.
This vulnerability falls under the CWE-79 category known as "Cross-site Scripting (XSS)" which is a widespread and well-documented security weakness in web applications and integrated development environments. The flaw enables attackers to inject malicious JavaScript code into notification messages that are subsequently rendered in the user's browser environment. The attack surface is particularly concerning given that Eclipse Theia is an integrated development environment and platform that developers trust with sensitive code and project information, making it an attractive target for exploitation. When a user receives a notification containing malicious JavaScript, the code executes within the context of the application's security boundaries, potentially allowing attackers to access sensitive data, modify user sessions, or perform unauthorized actions.
The operational impact of this vulnerability extends beyond simple script execution as it undermines the fundamental security model of the development environment. Attackers could craft malicious notification messages that appear legitimate to users, potentially leading to phishing attacks or session hijacking. The vulnerability is particularly dangerous in collaborative development environments where multiple developers may be using the same platform, as a single compromised notification could affect an entire team. Additionally, since Theia is designed for use in development contexts, the potential for attackers to exploit this vulnerability to gain access to source code repositories, configuration files, or other sensitive project data is significant. The JavaScript execution capability allows for sophisticated attacks that could establish persistent access or exfiltrate data without user interaction, making this a particularly insidious vulnerability.
Mitigation strategies for CVE-2021-28162 should prioritize immediate remediation through version updates to Eclipse Theia 0.16.1 or later, which contain the necessary HTML escaping fixes. Organizations should also implement additional defensive measures including input validation at multiple layers, regular security assessments of notification systems, and user education about the risks of interacting with untrusted notifications. Security teams should consider implementing content security policies and monitoring for suspicious notification patterns. The vulnerability demonstrates the importance of proper input sanitization in GUI frameworks and highlights the need for comprehensive security testing of user-facing components. Organizations should also review their deployment practices to ensure rapid patching of such vulnerabilities and establish incident response procedures specifically addressing UI-based XSS attacks in development environments. This vulnerability serves as a reminder that even development tools must maintain robust security hygiene to prevent exploitation of the trust placed in them by developers and organizations.