Description

SiYuan versions up to and including v3.7.2 (fixed in v3.7.4) contain an information disclosure vulnerability in the /api/asset/getFileAnnotation endpoint, which returns .sya PDF-annotation file content without a publish-access check. Because the endpoint is gated only by CheckAuth (unlike the /assets/* route, which enforces publish access and password), an anonymous reader (when publish authentication is disabled) or any publish RoleReader who knows an asset path can read the private PDF annotations (highlights and notes) of publish-forbidden, password-protected, or unpublished documents. The issue is limited to non-encrypted notebooks; encrypted-box annotations are not exposed.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "5.8",
  "pubDate": "2026-08-12T20:17:52.967Z",
  "pubdate": "2026-08-12T20:17:52.967Z",
  "executiveSummary": "SiYuan versions up to and including v3.7.2 contain an information disclosure vulnerability categorized as an authorization bypass leading to unauthorized data access. The vulnerability resides in the /api/asset/getFileAnnotation endpoint, which improperly exposes .sya PDF-annotation file contents without enforcing proper publish-access controls. Consequently, unauthorized entities can read private PDF annotations, including highlights and notes, belonging to publish-forbidden, password-protected, or unpublished documents. The impact is limited to non-encrypted notebooks, as encrypted-box annotations remain unexposed. The risk implications include the leakage of sensitive user research, personal notes, and confidential annotations associated with protected documents. Attacker capabilities range from anonymous readers (when publish authentication is disabled) to authenticated publish RoleReader users who possess knowledge of the target asset path. Exploitation requirements involve sending a targeted request to the unvalidated API endpoint, bypassing standard document-level restrictions implemented elsewhere in the application.",
  "technicalDetails": "The vulnerability is rooted in a discrepancy in access control implementation across routing components within SiYuan. Specifically, the /assets/* route correctly enforces comprehensive publish-access checks and password validation mechanisms. In contrast, the vulnerable /api/asset/getFileAnnotation endpoint is gated solely by the generic CheckAuth function. This insufficient authorization check allows callers who satisfy the base authentication middleware to bypass document-level confidentiality boundaries.\nThe vulnerable component is the asset management and annotation retrieval subsystem handling .sya files. Affected versions comprise SiYuan up to and including v3.7.2, with the issue being officially remediated in v3.7.4. The attack requires network exposure of the SiYuan application instance and relies on the attacker knowing or enumerating the valid asset path corresponding to the targeted document.\nThe step-by-step attack flow proceeds as follows: First, an attacker identifies or guesses the asset path of a private, unpublished, or password-protected document within a non-encrypted notebook. Second, the attacker interacts with the network-exposed SiYuan server, targeting the /api/asset/getFileAnnotation endpoint. Third, because the endpoint relies strictly on basic CheckAuth validation rather than verifying document publish permissions or password compliance, the application processes the request. Finally, the server retrieves and returns the raw contents of the corresponding .sya PDF-annotation file, exposing sensitive highlights and notes to the unauthorized requestor. The post-exploitation impact is restricted to the disclosure of textual annotation data contained within the retrieved .sya files, while encrypted-box annotations remain secure and inaccessible."
}