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 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" 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: 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.