CVE-2026-50138

# WebDAV listener ignores `--read-only`, `--upload-only`, and `--no-delete` mode flags **Ecosystem:** Go **Package:** `goshs.de/goshs/v2` (`github.com/patrickhener/goshs`) **Affected:** `<= v2.0.9` (every release that ships the WebDAV handler) ## Summary When `goshs` is launched with WebDAV enabled (`-w`), the mode-restriction flags `--read-only`, `--upload-only`, and `--no-delete` are enforced only on the primary HTTP port. The WebDAV port is wired straight to `golang.org/x/net/webdav.Handler` with no equivalent guard, so an authenticated WebDAV client can `PUT`, `DELETE`, `MKCOL`, `MOVE`, and `COPY` despite the operator's stated intent. ## Details [`httpserver/server.go:207-238`](https://github.com/patrickhener/goshs/blob/v2.0.9/httpserver/server.go#L207-L238) — the WebDAV mux registers only `IPWhitelistMiddleware`, `ServerHeaderMiddleware`, and optionally `BasicAuthMiddleware`. There is no `fs.ReadOnly || fs.UploadOnly || fs.NoDelete` check on the WebDAV path. The HTTP mux in the same file (lines 134-204) does check these flags on every state-changing route. ## Proof of concept ```bash mkdir -p /tmp/r && echo secret > /tmp/r/x.txt goshs -p 18000 -wp 18001 -w -ro -d /tmp/r -b admin:pw & curl -u admin:pw -X PUT http://localhost:18000/y.txt --data x # 403 (HTTP enforces -ro) curl -u admin:pw -X PUT http://localhost:18001/y.txt --data x # 201 (WebDAV writes anyway) curl -u admin:pw -X DELETE http://localhost:18001/x.txt # 204 (WebDAV deletes anyway) curl -u admin:pw -X MKCOL http://localhost:18001/pwned/ # 201 (WebDAV creates dir) ``` ## Impact - **Integrity** — `--read-only` and `--no-delete` are silently downgraded to "no protection" on the WebDAV port. Any WebDAV client (curl, cadaver, Windows Explorer, Finder) can overwrite/delete files. - **Confidentiality** — `--upload-only` is also bypassed: WebDAV GET/PROPFIND still return file contents. - **Trust** — operators using `goshs -w -ro -d /srv/case-files -b reviewer:pw