GHSA-gc3j-79f2-7vvw is a high-severity (CVSS 7.7) CWE-284 vulnerability in github.com/fission/fission. O3 Security confirms whether GHSA-gc3j-79f2-7vvw is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Fission: Cross-namespace event leakage via KubernetesWatchTrigger allows persistent tenant surveillance
Real-World Exposure
github.com/fission/fissionReal-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
Summary
A low-privilege developer who could create a KubernetesWatchTrigger (KWT) in their own namespace was able to establish a persistent surveillance channel over any other namespace.
Details
Two independent flaws compounded:
pkg/kubewatcher/kubewatcher.go::createKubernetesWatchusedw.Spec.Namespace(user-controlled) directly as the Watch target without checking it againstw.Namespace(the KWT's own namespace).kubewatcherestablished the Watch using its cluster-scoped service account and serialized every Pod/Service/Job change event as full JSON over HTTP POST to the attacker's function.- The validating webhook (
pkg/webhook/kuberneteswatchtrigger.go) registeredverbs=createonly, soupdate/patchrequests bypassed validation entirely.
A separate leak: an empty spec.namespace resolved to all namespaces via the controller's default, letting an attacker omit the field to surveil the entire cluster.
Impact
A tenant with kuberneteswatchtriggers.fission.io/create could continuously receive full event payloads for Pods, Services, and Jobs in any namespace — a persistent cross-tenant surveillance channel requiring no additional privileges.
Fix
Fixed in #3379 and released in v1.24.0.
- The validating webhook marker is extended to
verbs=create;update. ValidaterejectsKubernetesWatchTrigger.spec.namespace != metadata.namespace.- A controller guard in
createKubernetesWatchrejects cross-namespace targets that bypass admission and coerces an emptySpec.Namespaceto the trigger's own namespace.
Behavioural change
KubernetesWatchTriggers with an unset spec.namespace now watch only their own namespace instead of all namespaces. Anyone relying on the previous all-namespaces behaviour must create a separate KWT per namespace.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/fission/fission | all versions | 1.24.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/fission/fission. 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 github.com/fission/fission to 1.24.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-gc3j-79f2-7vvw 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-gc3j-79f2-7vvw 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-gc3j-79f2-7vvw. 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-gc3j-79f2-7vvw in your dependencies?
O3 detects GHSA-gc3j-79f2-7vvw across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.