CVE-2024-45621 in Rocket.Chat
Summary
by MITRE • 09/02/2024
The Electron desktop application of Rocket.Chat through 6.3.4 allows stored XSS via links in an uploaded file, related to failure to use a separate browser upon encountering third-party external actions from PDF documents.
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Analysis
by VulDB Data Team • 06/15/2025
The vulnerability identified as CVE-2024-45621 affects the Rocket.Chat desktop application version 6.3.4 and earlier, representing a critical stored cross-site scripting flaw that arises from inadequate handling of external links within uploaded files. This issue specifically manifests when users encounter PDF documents containing malicious hyperlinks that trigger third-party external actions, creating a persistent security risk that can compromise user sessions and execute unauthorized code within the application's context. The vulnerability stems from the application's failure to properly isolate external content through a dedicated browser instance, instead allowing potentially malicious links to execute within the same security context as the legitimate application interface.
The technical implementation of this vulnerability involves the Electron framework's browser window management where external actions from PDF documents are not properly sandboxed or redirected to a separate browser process. When users open PDF files containing malicious links, the application fails to implement proper content security policies that would normally prevent cross-site scripting attacks. This flaw allows attackers to embed malicious JavaScript within PDF documents that executes when users click on links or interact with embedded elements, effectively bypassing the application's security boundaries. The stored nature of this vulnerability means that malicious payloads can persist within uploaded files and affect any user who accesses them, creating a widespread risk across all application users.
The operational impact of this vulnerability extends beyond simple code execution to encompass full session hijacking capabilities and potential data exfiltration. Attackers can craft malicious PDF documents that, when opened by victims, execute scripts that steal authentication tokens, access local storage, or redirect users to malicious sites that can harvest sensitive information. The threat landscape is particularly concerning given that PDF documents are commonly shared in enterprise environments where Rocket.Chat is deployed, making this vulnerability exploitable through social engineering campaigns that target users with seemingly legitimate documents. This vulnerability directly relates to CWE-79 which defines cross-site scripting flaws, and maps to ATT&CK technique T1566 for social engineering and T1059 for command and scripting interpreter usage, creating a comprehensive attack vector that combines document manipulation with execution techniques.
Mitigation strategies for CVE-2024-45621 should focus on implementing proper browser isolation for external content, particularly PDF documents, through Electron's native browser window management capabilities. Organizations should enforce strict content security policies that prevent external links from executing within the application context and implement automatic redirection to secure browser instances for all third-party content. The recommended approach includes updating to Rocket.Chat version 6.3.5 or later where this vulnerability has been addressed through proper external action handling, implementing network-level controls that filter suspicious content, and establishing user education programs that warn against opening untrusted PDF documents. Additionally, administrators should configure the application to disable automatic execution of external actions and implement sandboxing measures that isolate external content processing from the core application interface. The solution should also incorporate monitoring for suspicious file upload patterns and implement automated scanning of uploaded content to identify potentially malicious documents before they can be accessed by other users.