GHSA-2p4g-jrmx-r34m is a medium-severity (CVSS 4.7) vulnerability in github.com/rancher/rancher. 3 public exploit references exist, so weaponization risk is real. O3 Security confirms whether GHSA-2p4g-jrmx-r34m is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Rancher Login Parameter Can Be Edited
Real-World Exposure
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 vulnerability exists in Rancher 2.1.4 in the login component, where the errorMsg parameter can be tampered to display arbitrary content, filtering tags but not special characters or symbols. There's no other limitation of the message, allowing malicious users to lure legitimate users to visit phishing sites with scare tactics, e.g., displaying a "This version of Rancher is outdated, please visit https://malicious.rancher.site/upgrading" message.
PoC
- Access the following endpoint on any Rancher instance up to 2.1.4:
https://RANCHER:PORT/login?errorMsg=%68%74%74%70%73%3a%2f%2f%77%77%77%2e%6f%77%61%73%70%2e%6f%72%67%2f%69%6e%64%65%78%2e%70%68%70%2f%57%65%62%5f%50%61%72%61%6d%65%74%65%72%5f%54%61%6d%70%65%72%69%6e%67
It will display a link to OWASP Wiki explaining Web Parameter Tampering.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/rancher/rancher | all versions | No fix |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
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.
Remediation status
No patched version of github.com/rancher/rancher has shipped for GHSA-2p4g-jrmx-r34m yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
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-2p4g-jrmx-r34m 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-2p4g-jrmx-r34m. 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-2p4g-jrmx-r34m in your dependencies?
O3 detects GHSA-2p4g-jrmx-r34m across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.