SiYuan is a personal knowledge management system. Prior to 3.5.10, a path traversal vulnerability in the /export endpoint allows an attacker to read arbitrary files from the server filesystem. By exploiting double‑encoded traversal sequences, an attacker can access sensitive files such as conf/conf.json, which contains secrets including the API token, cookie signing key, and workspace access authentication code. Leaking these secrets may enable administrative access to the SiYuan kernel API, and in certain deployment scenarios could potentially be chained into remote code execution (RCE). This vulnerability is fixed in 3.5.10.

Affected: Go: github.com/siyuan-note/siyuan/kernel

### Summary A path traversal vulnerability in the `/export` endpoint allows an attacker to read arbitrary files from the server filesystem. By exploiting double‑encoded traversal sequences, an attacker can access sensitive files such as `conf/conf.json`, which contains secrets including the API token, cookie signing key, and workspace access authentication code.

Leaking these secrets may enable administrative access to the SiYuan kernel API, and in certain deployment scenarios could potentially be chained into `remote code execution (RCE)`.

### Details File: [serve.go](app://-/index.html?hostId=local#), [session.go](app://-/index.html?hostId=local#) Lines: serve.go 303, 315, 320, 340, 955-957; session.go 292-295

Vulnerable Code: ``` // session.go if localhost { if strings.HasPrefix(c.Request.RequestURI, "/assets/") || strings.HasPrefix(c.Request.RequestURI, "/export/") { c.Set(RoleContextKey, RoleAdministrator) c.Next() return } }

// serve.go filePath := strings.TrimPrefix(c.Request.URL.Path, "/export/") decodedPath, err := url.PathUnescape(filePath) fullPath := filepath.Join(exportBaseDir, decodedPath) c.File(fullPath)

// CORS c.Header("Access-Control-Allow-Origin", "*")

``` Points of Vulnerability:

- `/export/*` trusts url.PathUnescape output and joins it without enforcing fullPath to stay under exportBaseDir. - Double-encoded traversal (`%252e%252e`) bypasses `ServeFile` dot-dot URL rejection but is decoded by app logic into ... - `C…