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Rancher 'Audit Log' leaks sensitive information

High
andypitcher published GHSA-xfj7-qf8w-2gcr Feb 8, 2024

Package

gomod rancher/rancher (Go)

Affected versions

>=2.6.0, <2.6.14
>=2.7.0, < 2.7.10
>=2.8.0, <2.8.2

Patched versions

2.6.14
2.7.10
2.8.2

Description

Impact

A vulnerability has been identified which may lead to sensitive data being leaked into Rancher's audit logs. Rancher Audit Logging is an opt-in feature, only deployments that have it enabled and have AUDIT_LEVEL set to 1 or above are impacted by this issue.

The leaks might be caught in the audit logs upon these actions:

  • Creating cloud credentials or new authentication providers. It is crucial to note that all authentication providers (such as AzureAD) and cloud providers (such as Google) are impacted.
  • Downloading a kubeconfig file from a downstream or a local cluster.
  • Logging in/out from Rancher.

The affected data may include the following:

  • HTTP headers
Field Location
X-Api-Auth-Header Request header
X-Api-Set-Cookie-Header Response header
X-Amz-Security-Token Request header
credentials Request body
applicationSecret Request Body
oauthCredential Request Body
serviceAccountCredential Request Body
spKey Request Body
spCert Request body
spCert Response body
certificate Request body
privateKey Request body
  • API Server calls returning Secret objects (including sub-types, such as kubernetes.io/dockerconfigjson).
  • Raw command lines used by agents to connect to the Rancher server which expose sensitive information (e.g. register ... --token abc).
  • Kubeconfig contents when the 'Download KubeConfig' feature is used in the Rancher UI.

The patched versions will redact the sensitive data, replacing it with [redacted], making it safer for consumption. It is recommended that static secrets are rotated after the system is patched, to limit the potential impact of sensitive data being misused due to this vulnerability.

Note:

  1. The severity of the vulnerability is intricately tied to the logging strategy employed. If logs are kept locally (default configuration), the impact is contained within the system, limiting the exposure.
    However, when logs are shipped to an external endpoint, the vulnerability's severity might increase, as resistance against leaks is contingent on the security measures implemented at the external log collector level.
  2. The final impact severity for confidentiality, integrity and availability is dependent on the permissions that the leaked credentials have on their own services.

Patches

Patched versions include releases 2.6.14, 2.7.10 and 2.8.2.

Workarounds

If AUDIT_LEVEL 1 or above is required and you cannot update to a patched Rancher version, ensure that the log is handled appropriately and it is not shared with other users or shipped into a log ingestion solution without the appropriate RBAC enforcement. Otherwise, disabling the Audit feature or decreasing it to the audit level 0, mitigates the issue.

For more information

If you have any questions or comments about this advisory:

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Local
Attack complexity
Low
Privileges required
High
User interaction
Required
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:L/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:H

CVE ID

CVE-2023-22649

Weaknesses