CVE-2021-25320
CRITICALCVE-2021-25320 is a critical-severity (CVSS 9.9) CWE-284 vulnerability in github.com/rancher/rancher. O3 Security confirms whether CVE-2021-25320 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Rancher cloud credentials can be used through proxy API by users without access
Blast Radius
github.com/rancher/rancher🐹github.com/rancher/rancherReal-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
A Improper Access Control vulnerability in Rancher, allows users in the cluster to make request to cloud providers by creating requests with the cloud-credential ID. Rancher in this case would attach the requested credentials without further checks This issue affects: Rancher versions prior to 2.5.9; Rancher versions prior to 2.4.16.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/rancher/rancher | ≥ 2.2.0&&< 2.4.16 | 2.4.16 |
| 🐹Go | github.com/rancher/rancher | ≥ 2.5.0&&< 2.5.9 | 2.5.9 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/rancher/rancher. 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/rancher/rancher to 2.4.16 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-25320 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 CVE-2021-25320 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 CVE-2021-25320. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2021-25320 in your dependencies?
O3 detects CVE-2021-25320 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.