CVE-2024-56359 in grist-core
Summary
by MITRE • 12/20/2024
grist-core is a spreadsheet hosting server. A user visiting a malicious document and clicking on a link in a HyperLink cell using a control modifier (meaning for example Ctrl+click) could have their account compromised, since the link could use the javascript: scheme and be evaluated in the context of their current page. This issue has been patched in version 1.3.2. Users are advised to upgrade. Users unable to upgrade should avoid clicking on HyperLink cell links using a control modifier in documents prepared by people they do not trust.
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Analysis
by VulDB Data Team • 03/13/2025
The vulnerability identified as CVE-2024-56359 affects grist-core, a spreadsheet hosting server platform that enables collaborative document editing and data management. This security flaw represents a sophisticated cross-site scripting attack vector that exploits user interaction patterns within spreadsheet applications. The vulnerability specifically targets the handling of HyperLink cells in spreadsheet documents, where users might inadvertently trigger malicious code execution through seemingly benign navigation actions.
The technical implementation of this vulnerability stems from insufficient input validation and sanitization of hyperlink URLs within the grist-core application. When a user encounters a malicious document containing a hyperlink cell with a javascript: scheme URL, the application fails to properly validate or sanitize this content before rendering it in the user's browser context. The vulnerability becomes exploitable when users interact with these links using control modifiers such as Ctrl+click, which bypasses normal security checks that would typically prevent javascript execution in web contexts. This behavior creates a dangerous scenario where malicious actors can craft documents containing hidden javascript payloads that execute within the user's authenticated session.
The operational impact of this vulnerability extends beyond simple data theft or manipulation. Since the attack requires user interaction through specific control modifier combinations, it represents a sophisticated social engineering vector that could lead to complete account compromise. An attacker could craft malicious documents that, when opened and interacted with using control modifiers, would execute javascript code that steals session cookies, redirects users to phishing sites, or performs unauthorized actions within the grist-core application. The vulnerability specifically targets the trust model of collaborative environments where users expect to safely interact with documents prepared by colleagues or partners, making it particularly dangerous in enterprise settings where document sharing is common.
This vulnerability aligns with CWE-79, which describes Cross-Site Scripting (XSS) flaws in web applications, and demonstrates how seemingly innocuous user interface elements can become attack vectors when proper input validation is absent. The ATT&CK framework categorizes this as a technique involving user interaction and privilege escalation through malicious document manipulation. The attack requires a specific user behavior pattern that makes it harder to detect automatically but easier to exploit in targeted social engineering campaigns. The fix implemented in version 1.3.2 addresses the core issue through enhanced URL validation and sanitization of hyperlink content, ensuring that javascript: schemes are properly handled and do not execute within the application context.
Organizations using grist-core should prioritize immediate upgrade to version 1.3.2 to eliminate this vulnerability. The mitigation strategy should also include user education about the dangers of clicking on hyperlinks in untrusted documents, particularly when using control modifiers. System administrators should monitor for potential exploitation attempts and implement additional security measures such as browser security policies that restrict javascript execution in web contexts. The vulnerability highlights the importance of validating all user-provided content in collaborative environments and demonstrates how seemingly simple user interface features can become significant security risks when proper security controls are not implemented.