GHSA-3whc-qvhv-xqjp goshs: WebDAV listener ignores --read-only, --upload-only, and --no-delete mode flags

• Go goshs.de/goshs/v2: < 2.1.0 → fixed in 2.1.0

WebDAV listener ignores `--read-only`, `--upload-only`, and `--no-delete` mode flags Ecosystem: Go Package: `goshs.de/goshs/v2` (`github.com/patrickhener/goshs`) Affected: ` /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` to deliver engagement artifacts believe the directory is immutable. It isn't. Suggested fix Add a small `http.HandlerFunc` in front of `wdHandler` that maps WebDAV verbs to the existing mode flags: ```go wdGuard := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { switch r.Method { case http.MethodPut, "MKCOL", "MOVE", "COPY": if fs.ReadOnly || fs.UploadOnly { http.Error(w, "read-only", 403); return } case http.MethodDelete: if fs.ReadOnly || fs.UploadOnly || fs.NoDelete { http.Error(w, "delete disabled", 403); return } case http.MethodGet, "PROPFIND", "HEAD": if fs.UploadOnly { http.Error(w, "upload-only", 403); return } } wdHandler.ServeHTTP(w, r) }) ``` Add regression tests in `integration/functions.go` covering each mode flag × each WebDAV verb. Reporter: Nishant Verma. Reproduced live against `goshs v2.0.9` (commit `8fc1e91`) on 2026-05-27.