GHSA-3whc-qvhv-xqjp
HIGHGHSA-3whc-qvhv-xqjp is a high-severity (CVSS 8.1) CWE-284 vulnerability in goshs.de/goshs/v2. O3 Security confirms whether GHSA-3whc-qvhv-xqjp is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
goshs: WebDAV listener ignores --read-only, --upload-only, and --no-delete mode flags
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for GHSA-3whc-qvhv-xqjp.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-3whc-qvhv-xqjp plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 372,324 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
goshs.de/goshs/v2Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
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 — 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-onlyand--no-deleteare silently downgraded to "no protection" on the WebDAV port. Any WebDAV client (curl, cadaver, Windows Explorer, Finder) can overwrite/delete files. - Confidentiality —
--upload-onlyis also bypassed: WebDAV GET/PROPFIND still return file contents. - Trust — operators using
goshs -w -ro -d /srv/case-files -b reviewer:pwto 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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | goshs.de/goshs/v2 | all versions | 2.1.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for goshs.de/goshs/v2. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update goshs.de/goshs/v2 to 2.1.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-3whc-qvhv-xqjp is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-3whc-qvhv-xqjp is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-3whc-qvhv-xqjp. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-3whc-qvhv-xqjp in your dependencies?
O3 detects GHSA-3whc-qvhv-xqjp across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.