CVE-2020-8292 in Rocket.Chat Server
Summary
by MITRE • 01/26/2021
Rocket.Chat server before 3.9.0 is vulnerable to a self cross-site scripting (XSS) vulnerability via the drag & drop functionality in message boxes.
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Analysis
by VulDB Data Team • 02/20/2021
The vulnerability identified as CVE-2020-8292 affects Rocket.Chat server versions prior to 3.9.0 and represents a critical self-cross-site scripting flaw that exploits the drag and drop functionality within message boxes. This vulnerability allows authenticated users to execute malicious scripts against themselves, creating a unique scenario where the victim becomes the target of their own actions. The flaw specifically manifests when users interact with the drag and drop interface in message composition areas, where improperly sanitized user input can be injected into the page context.
The technical implementation of this vulnerability stems from inadequate input validation and sanitization within the Rocket.Chat server's message handling system. When users drag and drop content into message boxes, the server fails to properly escape or filter potentially malicious content that may contain script tags or other XSS payloads. This weakness enables attackers to craft messages containing malicious JavaScript that executes in the context of the victim's browser session, leveraging the fact that the application does not adequately distinguish between legitimate user content and potentially harmful script code. The vulnerability is classified under CWE-79 as a failure to sanitize user input, specifically manifesting as a self-XSS attack vector.
The operational impact of this vulnerability extends beyond simple script execution, as it can be leveraged to perform various malicious activities within the context of the affected user's session. Attackers could potentially steal session cookies, redirect users to malicious sites, or execute other client-side attacks that compromise the integrity of the communication platform. Since the vulnerability affects the message composition functionality, it can be particularly dangerous in collaborative environments where users frequently exchange content. The self-XSS nature means that the attack requires user interaction, but once initiated, it can persist within the user's session until the browser is closed or the session expires.
Organizations utilizing Rocket.Chat server versions before 3.9.0 face significant security risks from this vulnerability, particularly in environments where sensitive communication occurs. The attack vector is relatively simple to exploit, requiring only that a user interacts with a maliciously crafted message containing the XSS payload. Security professionals should consider this vulnerability in relation to the ATT&CK framework, specifically under the T1059.007 technique for command and scripting interpreter, as it enables the execution of arbitrary code within user sessions. Mitigation strategies should include immediate deployment of the patched Rocket.Chat server version 3.9.0 or later, alongside enhanced input validation procedures and user education about the risks of interacting with untrusted content. Additionally, implementing Content Security Policy headers and regular security auditing of web application interfaces can help reduce the overall attack surface and prevent similar vulnerabilities from being exploited in the future.