CVE-2020-8288 in Rocket.Chat Server
Summary
by MITRE • 01/26/2021
The `specializedRendering` function in Rocket.Chat server before 3.9.2 allows a cross-site scripting (XSS) vulnerability by way of the `value` parameter.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 02/20/2021
The vulnerability identified as CVE-2020-8288 affects the Rocket.Chat server software prior to version 3.9.2, specifically within the specializedRendering function that processes user input through the value parameter. This represents a critical cross-site scripting flaw that enables attackers to inject malicious scripts into web pages viewed by other users. The vulnerability stems from insufficient input validation and output encoding mechanisms within the server-side rendering process, creating an avenue for persistent XSS attacks that can compromise user sessions and execute unauthorized actions.
The technical exploitation of this vulnerability occurs when malicious input is passed through the value parameter to the specializedRendering function, which fails to properly sanitize or encode the data before rendering it within the web interface. This flaw falls under CWE-79, which specifically addresses cross-site scripting vulnerabilities where untrusted data is incorporated into web pages without proper validation or encoding. The vulnerability exists because the application does not adequately filter user-supplied content, allowing attackers to inject HTML or JavaScript code that executes in the context of other users' browsers.
Operational impact of this vulnerability extends beyond simple script execution, as it can enable attackers to steal session cookies, perform actions on behalf of users, redirect victims to malicious sites, or even escalate privileges within the application. The persistent nature of this XSS vulnerability means that once exploited, malicious scripts can remain active in the application until manually removed or the affected version is patched. This creates ongoing security risks for organizations using vulnerable Rocket.Chat deployments, particularly in environments where users may have varying levels of access or where sensitive communication occurs through the platform.
Mitigation strategies for CVE-2020-8288 should prioritize immediate patching of the Rocket.Chat server to version 3.9.2 or later, which includes proper input sanitization and output encoding mechanisms. Organizations should also implement additional security controls such as content security policies, input validation at multiple layers, and regular security scanning of web applications. The vulnerability demonstrates the importance of proper secure coding practices and input validation as outlined in the OWASP Top Ten and MITRE ATT&CK framework, particularly in the context of web application security. Network segmentation and monitoring for suspicious user activity can provide additional defense-in-depth measures while the primary patch is being deployed across all affected systems.