Stored XSS in Dify Mermaid Diagrams Allows Code Execution

Executive Summary

This vulnerability affects Dify, an open-source LLM app development platform, in versions prior to 1.11.2. It is a stored Cross-Site Scripting (XSS) issue that occurs when rendering Mermaid diagrams within chats. The root cause is that Dify's default Mermaid configuration uses a security level set to 'loose', which permits potentially unsafe content to execute scripts. This can allow malicious code to be stored and later executed in the context of the application.

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Impact Analysis

The stored XSS vulnerability can allow attackers to inject malicious scripts into Mermaid diagrams that are rendered within chats. When other users view these diagrams, the malicious scripts can execute in their browsers, potentially leading to unauthorized actions such as stealing session tokens, performing actions on behalf of the user, or delivering malware. This can compromise user data and the integrity of the application.

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Compliance Impact

I don't know

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Detection Guidance

I don't know

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Mitigation Strategies

To mitigate this vulnerability, upgrade Dify to version 1.11.2 or later, where the stored XSS issue related to Mermaid diagrams is fixed by changing the default Mermaid configuration from securityLevel: loose to a more secure setting.

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