CVE-2021-36775
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · unediteda Improper Access Control vulnerability in SUSE Rancher allows users to keep privileges that should have been revoked. This issue affects: SUSE Rancher Rancher versions prior to 2.4.18; Rancher versions prior to 2.5.12; Rancher versions prior to 2.6.3.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceImproper Access Control vulnerability in SUSE Rancher that allows users to retain privileges (likely cluster-level or administrative permissions) that should have been revoked after role or membership changes. The access control system fails to properly enforce privilege revocation.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 2.4.18>= 2.5.0, < 2.5.12>= 2.6.0, < 2.6.3CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
-
Identify Rancher versionCheck the installed Rancher version via the UI (About Rancher page), Rancher CLI ('rancher --version'), or by inspecting the Rancher deployment in Kubernetes ('kubectl get deployment rancher -n cattle-system -o jsonpath={.spec.template.spec.containers[0].image}')Affected if The installed version is lower than 2.4.18, between 2.5.0 and 2.5.11 inclusive, or between 2.6.0 and 2.6.2 inclusive
-
Verify access control is enabledConfirm that authentication is configured in Rancher (Users & Authentication section). The vulnerability only affects environments where external authentication or role-based access control is in useAffected if Authentication providers (such as Active Directory, LDAP, or OAuth) are configured and users have been assigned roles that may have been modified or revoked
-
Review user role bindingsList all users and their role assignments in Rancher (Users > User Name > Kubernetes YAML). Check for cluster role bindings and project role bindings that may existAffected if There are users assigned to cluster-level or project-level roles, particularly those whose roles were recently changed or revoked
-
Audit recently modified rolesCompare current role bindings against known-good baselines or audit logs. Look for users who should no longer have access but still appear in role bindingsAffected if Any user who was assigned a role and subsequently had that role removed or modified still retains the original privilege level in the cluster role bindings
You are affected if your Rancher version falls within the vulnerable ranges AND you have users with role assignments that may have been revoked but not enforced.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped2.4.182.5.122.6.3
Upgrade Rancher to version 2.4.18 or later, 2.5.12 or later, or 2.6.3 or later to remediate the improper access control. Verify that revoked users no longer have unauthorized access.
Upgrade to Rancher 2.4.18 (if on 2.4.x), 2.5.12 (if on 2.5.x), or 2.6.3 (if on 2.6.x) - preferably the latest stable release in the respective branch
- Back up the Rancher environment (Rancher app, etcd database, and Kubernetes cluster state) before starting the upgrade
- Identify the current Rancher version by checking the Rancher UI (top-left corner) or running `kubectl get rancher -n cattle-system -o jsonpath='{.items[0].status.rancherVersion}'`
- Determine the appropriate upgrade path based on the current version: for 2.4.x versions upgrade to 2.4.18; for 2.5.x versions upgrade to 2.5.12; for 2.6.x versions upgrade to 2.6.3
- For Helm-based installations, add the Rancher Helm repository and upgrade using: `helm repo add rancher-stable https://rancher.com/static/charts` and `helm upgrade rancher rancher-stable/rancher --namespace cattle-system --version <new-version>`
- For Docker-based installations, stop the current container, pull the new image, and run it with the same persistent data volume
- After upgrade, verify access control by creating a test user, assigning privileges, then revoking them to confirm privileges are properly revoked
- Verify the Rancher UI is accessible and all clusters are reporting healthy status
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation3.0 h
- Implementation4.0 h
- Testing6.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,128.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-36775 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-36775 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data