CVE-2021-36775: Github.com/rancher/rancher Rancher's Failure To Delete Orphaned Vulnerability

HIGH
Advisory Identifier: GHSA-28g7-896h-695v
CVSS 8.0
CWE-284
Published
Advisory Summary

CVE-2021-36775 is a HIGH (CVSS 8.0) rancher's failure to delete orphaned vulnerability (CWE-284: Improper Access Control) affecting Github.com/rancher/rancher libraries in the Go ecosystem. The issue involves rancher's failure to delete orphaned role bindings does not revoke project level access from group based authentication. Remediation is available by upgrading affected packages to version 2.4.18, 2.5.12, 2.6.3.

CVE-2021-36775 at a Glance

CVE Identifier CVE-2021-36775
GHSA Identifier GHSA-28g7-896h-695v
Severity HIGH
CVSS v3.1 Base Score 8.0
CWE Classification CWE-284: Improper Access Control
Affected Product Github.com/rancher/rancher
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 8.0

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:R/S:U/C:H/I:H/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction Required (UI:R)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2021-36775

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: 2.4.18
Upgrade github.com/rancher/rancher to 2.4.18
github.com/rancher/rancher fixed: 2.5.12
Upgrade github.com/rancher/rancher to 2.5.12
github.com/rancher/rancher fixed: 2.6.3
Upgrade github.com/rancher/rancher to 2.6.3
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-2021-36775, 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 2.4.18), 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

### Impact This vulnerability only affects customers using group based authentication in Rancher versions up to and including 2.4.17, 2.5.11 and 2.6.2. When removing a Project Role associated to a group from a project, the bindings that grant access to cluster scoped resources for those subjects do not get deleted. This happens due to an incomplete authorization logic check. A user who is a member of an affected group with authenticated access to Rancher could use this to access resources they should no longer have access to. The exposure level will depend on the original permission level granted to the affected project role. ### Patches Patched versions include releases 2.4.18, 2.5.12, 2.6.3 and later versions. ### Workarounds Limit access in Rancher to trusted users. There is not a direct mitigation besides upgrading to the patched Rancher versions. ### References Cluster and project roles documentation for Rancher [2.6](https://rancher.com/docs/rancher/v2.6/en/admin-settings/rbac/cluster-project-roles/), [2.5](https://rancher.com/docs/rancher/v2.5/en/admin-settings/rbac/cluster-project-roles/) and [2.4](https://rancher.com/docs/rancher/v2.0-v2.4/en/admin-settings/rbac/cluster-project-roles/). ### For more information If you have any questions or comments about this advisory: * Reach out to [SUSE Rancher Security team](https://github.com/rancher/rancher/security/policy) for security related inquiries. * Open an issue in [Rancher](https://github.com/rancher/rancher/issues/new/choose) repository. * Verify our [support matrix](https://www.suse.com/suse-rancher/support-matrix/all-supported-versions/) and [product support lifecycle](https://www.suse.com/lifecycle/).

CVE-2021-36775 Affected Github.com/rancher/rancher Versions

3 component(s)
Fixed Versions:
2.4.182.5.122.6.3
Product / Package Ecosystem Affected Versions Fixed Version
github.com/rancher/rancher
Go
< 2.4.18
2.4.18
github.com/rancher/rancher
Go
≥ 2.5.0
< 2.5.12
2.5.12
github.com/rancher/rancher
Go
≥ 2.6.0
< 2.6.3
2.6.3

References

Frequently Asked Questions

What is CVE-2021-36775?
CVE-2021-36775 is a security vulnerability in Github.com/rancher/rancher involving Rancher's Failure to delete orphaned role bindings does not revoke project level access from group based authentication under CWE-284: Improper Access Control.
Which Github.com/rancher/rancher versions are affected?
Affected versions include releases prior to 2.4.18, 2.5.12, 2.6.3 across affected packages: github.com/rancher/rancher.
What version fixes CVE-2021-36775?
Upgrading to 2.4.18, 2.5.12, 2.6.3 (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 2.4.18, 2.5.12, 2.6.3. Upgrade your dependency to 2.4.18, 2.5.12, 2.6.3 or later.
What is the CVSS score of CVE-2021-36775?
CVE-2021-36775 has a CVSS v3.1 base score of 8.0 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2021-36775?
CVE-2021-36775 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-2021-36775?
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
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-28g7-896h-695v",
  "modified" : "2024-07-08T20:42:51Z",
  "published" : "2024-04-24T21:01:50Z",
  "aliases" : [ "CVE-2021-36775" ],
  "summary" : "Rancher's Failure to delete orphaned role bindings does not revoke project level access from group based authentication",
  "details" : "### Impact\nThis vulnerability only affects customers using group based authentication in Rancher versions up to and including 2.4.17, 2.5.11 and 2.6.2.\n\nWhen removing a Project Role associated to a group from a project, the bindings that grant access to cluster scoped resources for those subjects do not get deleted. This happens due to an incomplete authorization logic check. A user who is a member of an affected group with authenticated access to Rancher could use this to access resources they should no longer have access to. The exposure level will depend on the original permission level granted to the affected project role.\n\n### Patches\nPatched versions include releases 2.4.18, 2.5.12, 2.6.3 and later versions.\n\n### Workarounds\nLimit access in Rancher to trusted users. There is not a direct mitigation besides upgrading to the patched Rancher versions.\n\n### References\nCluster and project roles documentation for Rancher [2.6](https://rancher.com/docs/rancher/v2.6/en/admin-settings/rbac/cluster-project-roles/), [2.5](https://rancher.com/docs/rancher/v2.5/en/admin-settings/rbac/cluster-project-roles/) and [2.4](https://rancher.com/docs/rancher/v2.0-v2.4/en/admin-settings/rbac/cluster-project-roles/).\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Reach out to [SUSE Rancher Security team](https://github.com/rancher/rancher/security/policy) for security related inquiries.\n* Open an issue in [Rancher](https://github.com/rancher/rancher/issues/new/choose) repository.\n* Verify our [support matrix](https://www.suse.com/suse-rancher/support-matrix/all-supported-versions/) and [product support lifecycle](https://www.suse.com/lifecycle/).",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/rancher/rancher"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.4.18"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 2.4.17"
    }
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/rancher/rancher"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.5.0"
      }, {
        "fixed" : "2.5.12"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 2.5.11"
    }
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/rancher/rancher"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.6.0"
      }, {
        "fixed" : "2.6.3"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 2.6.2"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/rancher/rancher/security/advisories/GHSA-28g7-896h-695v"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-36775"
  }, {
    "type" : "WEB",
    "url" : "https://bugzilla.suse.com/show_bug.cgi?id=1189120"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/rancher/rancher"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-284" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2024-04-24T21:01:50Z",
    "nvd_published_at" : "2022-04-04T13:15:00Z"
  }
}