GHSA-rmxw-pq4x-3fvh is a high-severity (CVSS 7.5) CWE-862 vulnerability in github.com/patrickhener/goshs. O3 Security confirms whether GHSA-rmxw-pq4x-3fvh is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
goshs: File-based .goshs ACL authorization bypass via the ?bulk zip-download route (unauthenticated read; residual of GHSA-wvhv-qcqf-f3cx)
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.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for GHSA-rmxw-pq4x-3fvh.
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-rmxw-pq4x-3fvh 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 371,625 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
github.com/patrickhener/goshs🐹github.com/patrickhener/goshs/v2🐹goshs.de/goshs🐹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
GHSA-wvhv-qcqf-f3cx fixed the per-folder .goshs ACL bypass on the state-changing routes (PUT/POST upload/?mkdir/?delete) and added recursive ACL resolution, and its description states the read/list path correctly enforces .goshs. That premise does not hold for the ?bulk zip-download route. bulkDownload (httpserver/updown.go) takes one or more ?file= parameters, runs each through sanitizePath(fs.Webroot, file), and streams the contents back as a ZIP without ever calling findEffectiveACL/applyCustomAuth. It is dispatched from earlyBreakParameters (?bulk) before the normal doDir/doFile/sendFile flow that performs the ACL check. An unauthenticated attacker can therefore read any file under the webroot protected solely by a .goshs ACL, bypassing both the folder auth (401 on the normal path) and the per-file block list (404 on the normal path). Same authorization-inconsistency root cause as the original advisory, surviving on a read route the fix did not cover.
Proof of concept (live, against the fixed v2.1.0 build which includes fix commit f212c4f4, served with no global -b auth, only a per-folder .goshs): GET /protected/secret.txt -> 401 (ACL enforced on normal path) GET /protected/secret.txt -u admin:admin -> 200 GET /?bulk&file=/protected/secret.txt -> 200, zip contains the protected file contents (BYPASS) GET /?bulk&file=/protected/blocked.txt -> 200, zip contains the block-listed file (block bypass) GET /protected/secret.txt?share -> 403 'Sharing disabled when auth is disabled' (correctly gated, NOT a bypass)
Impact: any unauthenticated network attacker can read files an operator protected with the documented per-folder .goshs ACL/basic-auth feature, by requesting them through ?bulk. Confidentiality only (the write/delete equivalents were closed by GHSA-wvhv-qcqf-f3cx). Applies to deployments relying on .goshs as the access boundary (a server-wide -b basic auth, if configured, also gates ?bulk via its middleware).
Remediation: enforce the effective .goshs ACL inside bulkDownload for every requested file exactly as sendFile/processDir do (resolve findEffectiveACL(filepath.Dir(absPath)) + applyCustomAuth + honor acl.Block), or route ?bulk through the same authorization gate as the normal read path. Audit ?cbDown and other alternate read routes for the same gap.
Credit: anir0y (independent security research).
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/patrickhener/goshs | all versions | No fix |
| 🐹Go | github.com/patrickhener/goshs/v2 | all versions | 2.1.1 |
| 🐹Go | goshs.de/goshs | all versions | No fix |
| 🐹Go | goshs.de/goshs/v2 | all versions | 2.1.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/patrickhener/goshs. 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
No patched version of github.com/patrickhener/goshs has shipped for GHSA-rmxw-pq4x-3fvh yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
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-rmxw-pq4x-3fvh 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-rmxw-pq4x-3fvh. 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-rmxw-pq4x-3fvh in your dependencies?
O3 detects GHSA-rmxw-pq4x-3fvh across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.