Security readout for executives and security teams
Plain-English summary
Rancher stored some cluster template answer credentials in cleartext and exposed them through APIs. An authenticated user with common cluster or project roles could read passwords, API tokens, or credentials they should not see, creating risk of broader account or infrastructure compromise.
Executive priority
Treat this as urgent for any Rancher-managed production environment. The business risk is credential disclosure to authenticated internal or tenant users, with possible downstream compromise of Kubernetes clusters, cloud APIs, or connected services.
Technical view
CVE-2021-36783 is CWE-522 in SUSE Rancher. Cluster Owners, Cluster Members, Project Owners, and Project Members could read cleartext credentials stored in cluster template answers through API endpoints. Affected versions are Rancher prior to 2.6.4 and prior to 2.5.13. CVSS 3.1 is 9.9.
Likely exposure
Exposure is most likely in environments running Rancher 2.6.x before 2.6.4 or 2.5.x before 2.5.13, especially where cluster templates stored secrets, passwords, or API tokens in answers and project or cluster membership is broadly assigned.
Exploitation context
The provided sources do not show CISA KEV listing or confirmed active exploitation. The issue is still high urgency because exploitation requires only authenticated low-privilege Rancher roles and can reveal reusable credentials or tokens.
Researcher notes
Evidence supports credential exposure via API endpoints to authenticated Rancher roles, but the bundle does not include endpoint details, exploit proof, or telemetry proving exploitation. Focus validation on affected versions, role scope, and whether cluster template answers contained sensitive credentials.
Mitigation direction
- Upgrade Rancher to 2.6.4 or later, or 2.5.13 or later.
- Review the Rancher advisory for any version-specific vendor guidance.
- Rotate credentials, passwords, and API tokens stored in affected cluster template answers.
- Reduce Cluster Member and Project Member access to only required users.
- Remove sensitive values from template answers where operationally possible.
Validation and detection
- Inventory Rancher server versions and identify instances below 2.6.4 or 2.5.13.
- Review cluster template answers for stored secrets, passwords, and API tokens.
- Confirm which users hold Cluster Owner, Cluster Member, Project Owner, or Project Member roles.
- Check audit logs for suspicious access to affected API resources.
- Verify upgraded environments no longer expose cleartext template answer credentials.
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
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-522: Credential and account abuse lookup
Authentication and credential weaknesses can make valid-account abuse and credential telemetry useful review starting points. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-36783 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.9 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/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:C/C:H/I:H/A:H3.16Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
9.9CriticalVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://bugzilla.suse.com/show_bug.cgi?id=1193990CVE reference
- https://github.com/rancher/rancher/security/advisories/GHSA-8w87-58w6-hfv8CVE reference
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.
Insufficiently Protected Credentials
Insufficiently Protected Credentials represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.