CVE-2021-25320: Github.com/rancher/rancher Rancher Cloud Credentials Can Be Vulnerability

CRITICAL
Advisory Identifier: GHSA-gqf8-rvrh-g7w6
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CVSS 9.9
CWE-284
Published
Advisory Summary

CVE-2021-25320 is a CRITICAL (CVSS 9.9) rancher cloud credentials can be vulnerability (CWE-284: Improper Access Control) affecting Github.com/rancher/rancher libraries in the Go ecosystem. The issue involves rancher cloud credentials can be used through proxy api by users without access. Remediation is available by upgrading affected packages to version 2.4.16, 2.5.9.

CVE-2021-25320 at a Glance

CVE Identifier CVE-2021-25320
GHSA Identifier GHSA-gqf8-rvrh-g7w6
Severity CRITICAL
CVSS v3.1 Base Score 9.9
CWE Classification CWE-284: Improper Access Control
Affected Product Github.com/rancher/rancher
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 9.9

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Changed (S:C)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2021-25320

To remediate this vulnerability, upgrade all affected Github.com/rancher/rancher dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

github.com/rancher/rancher fixed: 2.4.16 
Upgrade github.com/rancher/rancher to 2.4.16
github.com/rancher/rancher fixed: 2.5.9 
Upgrade github.com/rancher/rancher to 2.5.9
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for github.com/rancher/rancher

How to Check if You Are Affected

To determine whether your application is affected by CVE-2021-25320, inspect your project dependencies for Github.com/rancher/rancher:

inspect dependencies for github.com/rancher/rancher

Analyze the terminal output to locate any version of Github.com/rancher/rancher in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.4.16), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-284: Improper Access Control, where the product does not restrict or incorrectly restricts access to a resource from an unauthorized actor. In Github.com/rancher/rancher, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

A vulnerability was discovered in Rancher 2.2.0 through the aforementioned patched versions, where cloud credentials weren't being properly validated through the Rancher API. Specifically through a proxy designed to communicate with cloud providers. Any Rancher user that was logged-in and aware of a cloud-credential ID that was valid for a given cloud provider, could call that cloud provider's API through the proxy API, and the cloud-credential would be attached. The exploit is limited to valid Rancher users. There is not a direct mitigation outside of upgrading to the patched Rancher versions.

CVE-2021-25320 Affected Github.com/rancher/rancher Versions

2 component(s)
Fixed Versions:
2.4.162.5.9
Product / Package Ecosystem Affected Versions Fixed Version
github.com/rancher/rancher
golang/github.com/rancher/rancher
Go
≥ 2.2.0
< 2.4.16
2.4.16
github.com/rancher/rancher
golang/github.com/rancher/rancher
Go
≥ 2.5.0
< 2.5.9
2.5.9

References

GitHub Advisory / Wiki ADVISORY
https://github.com/rancher/rancher/security/advisories/GHSA-gqf8-rvrh-g7w6
NVD — CVE-2021-25320 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-25320
bugzilla.suse.com/show_bug.cgi WEB
https://bugzilla.suse.com/show_bug.cgi?id=1185514
Github.com/rancher/rancher Source Repository REPOSITORY
https://github.com/rancher/rancher

Frequently Asked Questions

What is CVE-2021-25320?
CVE-2021-25320 is a security vulnerability in Github.com/rancher/rancher involving Rancher cloud credentials can be used through proxy API by users without access under CWE-284: Improper Access Control.
Which Github.com/rancher/rancher versions are affected?
Affected versions include releases prior to 2.4.16, 2.5.9 across affected packages: github.com/rancher/rancher.
What version fixes CVE-2021-25320?
Upgrading to 2.4.16, 2.5.9 (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/rancher/rancher affected?
Yes, github.com/rancher/rancher is affected in releases prior to 2.4.16, 2.5.9. Upgrade your dependency to 2.4.16, 2.5.9 or later.
What is the CVSS score of CVE-2021-25320?
CVE-2021-25320 has a CVSS v3.1 base score of 9.9 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.
What CWE is associated with CVE-2021-25320?
CVE-2021-25320 is classified under CWE-284: Improper Access Control (The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.).
How can I check Go dependencies for CVE-2021-25320?
Run the dependency tree command: 'inspect dependencies for github.com/rancher/rancher'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-gqf8-rvrh-g7w6",
  "modified" : "2026-03-03T14:52:15Z",
  "published" : "2026-03-03T14:52:15Z",
  "aliases" : [ "CVE-2021-25320" ],
  "summary" : "Rancher cloud credentials can be used through proxy API by users without access",
  "details" : "A vulnerability was discovered in Rancher 2.2.0 through the aforementioned patched versions, where cloud credentials weren't being properly validated through the Rancher API. Specifically through a proxy designed to communicate with cloud providers. Any Rancher user that was logged-in and aware of a cloud-credential ID that was valid for a given cloud provider, could call that cloud provider's API through the proxy API, and the cloud-credential would be attached. The exploit is limited to valid Rancher users. There is not a direct mitigation outside of upgrading to the patched Rancher versions.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/rancher/rancher"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.2.0"
      }, {
        "fixed" : "2.4.16"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/rancher/rancher"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.5.0"
      }, {
        "fixed" : "2.5.9"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/rancher/rancher/security/advisories/GHSA-gqf8-rvrh-g7w6"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-25320"
  }, {
    "type" : "WEB",
    "url" : "https://bugzilla.suse.com/show_bug.cgi?id=1185514"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/rancher/rancher"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-284" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-03-03T14:52:15Z",
    "nvd_published_at" : "2021-07-15T09:15:00Z"
  }
}