SiYuan Embed Block Content Exposure via Publish Access

Executive Summary

SiYuan versions before v3.7.4 have a flaw where the getBlockDOMWithEmbed and getBlockDOMsWithEmbed endpoints do not properly filter embedded block content based on publish access permissions. This allows attackers to request published blocks containing embed queries and read content from password-protected, hidden, or forbidden documents without authorization.

Useful 0 Not Useful 0

Detection Guidance

To detect this vulnerability, check if your SiYuan instance is running a version before v3.7.4. Use commands like 'curl -X POST http://localhost:6806/api/block/getBlockDOMWithEmbed -d {"id":"test"}' to test if restricted content is exposed. Monitor logs for unauthorized access attempts to these endpoints.

Useful 0 Not Useful 0

Impact Analysis

This vulnerability can lead to unauthorized access to sensitive information stored in restricted documents. Attackers could view private notes, passwords, or other confidential data by exploiting the missing authorization checks in embedded block content requests.

Useful 0 Not Useful 0

Compliance Impact

This vulnerability could result in non-compliance with data protection regulations like GDPR or HIPAA by exposing sensitive personal or health information to unauthorized parties. Organizations using affected SiYuan versions may face legal and regulatory penalties due to unauthorized data disclosure.

Useful 0 Not Useful 0

Mitigation Strategies

Immediately upgrade SiYuan to version v3.7.4 or later. If upgrading is not possible, restrict network access to the vulnerable endpoints or disable embedded block features until patched. Review logs for potential exploitation attempts.

Useful 0 Not Useful 0