Executive brief
SiYuan is a personal knowledge management application that stores notebooks and configuration data within a workspace directory. An authenticated administrator can exploit a path traversal vulnerability in the setNotebookIcon API endpoint to write files outside the workspace boundary, potentially to system directories, temporary folders, or other sensitive locations. This could enable arbitrary directory creation and configuration tampering on the server.
Technical details
The setNotebookIcon endpoint in kernel/api/notebook.go binds the notebook parameter directly to boxID without applying the util.InvalidIDPattern validation guard that all sibling handlers enforce. The unvalidated boxID is passed to model.SetBoxIcon, which constructs a Box struct with the traversal-laden ID and calls saveConf0. This function uses filepath.Join(util.DataDir, boxID, ".siyuan", "conf.json"), which cleans but does not reject directory traversal sequences, allowing ".." segments to escape the workspace data directory and write to arbitrary filesystem locations writable by the kernel process.
Affected products
- siyuan-note SiYuan before v3.8.4
Timeline
- 2026-09-26: disclosed
- 2026-09-26: patched: v3.8.4 released with fix