Security readout for executives and security teams
Plain-English summary
This flaw lets Rancher users keep access that administrators intended to revoke. When group-associated project role bindings are deleted, matching Kubernetes RoleBindings may remain, leaving stale permissions active. For executives, the concern is failed access removal in affected Rancher environments, especially where group-based project access is used.
Executive priority
Treat this as high priority for Rancher environments managing sensitive or production clusters. The business risk is that access removal may not actually remove access, undermining least privilege and offboarding controls.
Technical view
CVE-2021-36775 is an improper access control issue in SUSE Rancher. Deleting PRTBs associated with a group does not delete corresponding RoleBindings, so privileges can persist after revocation. CVSS 3.1 is 8.8 with network attack vector, low required privileges, no user interaction, and high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is likely limited to SUSE Rancher versions before 2.4.18, 2.5.12, and 2.6.3, especially deployments using group-based project role bindings. Environments without affected Rancher versions or without relevant group-based access changes are less likely exposed.
Exploitation context
The provided sources do not show CISA KEV listing or active exploitation evidence. The CVSS vector indicates an authenticated, low-privileged network attacker could benefit from retained authorization, but the bundle does not provide exploit details or observed attack activity.
Researcher notes
The core issue is authorization state drift between Rancher PRTB deletion and Kubernetes RoleBinding cleanup. Public detail in the bundle is limited; avoid assuming exploit chains, impacted configurations beyond Rancher, or additional mitigations not stated by SUSE or CVE sources.
Mitigation direction
- Upgrade affected Rancher deployments to 2.4.18, 2.5.12, 2.6.3, or later as applicable.
- Review SUSE Rancher vendor guidance for any version-specific remediation notes.
- Audit group-based Rancher project role bindings for stale permissions.
- Remove unintended residual RoleBindings after confirming business ownership.
- Prioritize remediation where Rancher controls production Kubernetes clusters.
Validation and detection
- Inventory Rancher versions and compare them with the affected version thresholds.
- Identify projects using group-associated PRTBs for access management.
- After revoking group access, verify matching RoleBindings are removed.
- Review current RoleBindings for users or groups that should no longer have access.
- Confirm remediation in a non-production Rancher environment where possible.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
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ATT&CK lookup starting points
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CWE-284: Authorization and privilege behavior lookup
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Open ATT&CK lookupCVE-2021-36775 mapping review
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Open ATT&CK lookup- Severity
- High
- CVSS
- 8.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H2.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.8HighVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://bugzilla.suse.com/show_bug.cgi?id=1189120CVE reference · x_refsource_CONFIRM
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Access Control
Improper Access Control represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.