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Rancher's RKE1 Encryption Config kept in plain-text within cluster AppliedSpec

High severity GitHub Reviewed Published Jun 17, 2024 in rancher/rancher • Updated Oct 16, 2024

Package

gomod github.com/rancher/rancher (Go)

Affected versions

>= 2.7.0, < 2.7.14
>= 2.8.0, < 2.8.5

Patched versions

2.7.14
2.8.5

Description

Impact

This issue is only relevant to clusters provisioned using RKE1 with secrets encryption configuration enabled.

A vulnerability has been identified in which an RKE1 cluster keeps constantly reconciling when secrets encryption configuration is enabled (please see the RKE documentation). When reconciling, the Kube API secret values are written in plaintext on the AppliedSpec. Cluster owners, Cluster members, and Project members (for projects within the cluster), all have RBAC permissions to view the cluster object from the apiserver.

This could lead to an unauthorized user gaining access to the entire secrets encryption config specific for the cluster, only on the applied spec.

Since this affects only custom encryption configurations, users need to manually rotate the keys by editing the cluster. For more information, please refer to the RKE secrets encryption documentation.

The full custom configuration example:

services:
  kube-api:
    secrets_encryption_config:
      enabled: true
      custom_config:
        apiVersion: apiserver.config.k8s.io/v1
        kind: EncryptionConfiguration
        resources:
        - resources:
          - secrets
          providers:
          - aescbc:
              keys:
              - name: k-fw5hn
                secret: RTczRjFDODMwQzAyMDVBREU4NDJBMUZFNDhCNzM5N0I= #<--- needs to be changed
          - identity: {}

Please consult the associated MITRE ATT&CK - Technique - Unsecured Credentials for further information about this category of attack.

Patches

To address this issue, the fix introduces a new change that copies the AppliedSpec before mutating. As such, the next time the cluster is reconciled and the AppliedSpec is set, all references to sensitive data will be removed.

Patched versions include releases 2.7.14 and 2.8.5.

Workarounds

There are no workarounds for this issue. Users are recommended to upgrade, as soon as possible, to a version of RKE/Rancher Manager which contains the fixes.

References

If you have any questions or comments about this advisory:

References

@pdellamore pdellamore published to rancher/rancher Jun 17, 2024
Published to the GitHub Advisory Database Jun 17, 2024
Reviewed Jun 17, 2024
Published by the National Vulnerability Database Oct 16, 2024
Last updated Oct 16, 2024

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 v4 base metrics

Exploitability Metrics
Attack Vector Network
Attack Complexity Low
Attack Requirements None
Privileges Required Low
User interaction None
Vulnerable System Impact Metrics
Confidentiality High
Integrity None
Availability None
Subsequent System Impact Metrics
Confidentiality None
Integrity None
Availability None

CVSS v4 base metrics

Exploitability Metrics
Attack Vector: This metric reflects the context by which vulnerability exploitation is possible. This metric value (and consequently the resulting severity) will be larger the more remote (logically, and physically) an attacker can be in order to exploit the vulnerable system. The assumption is that the number of potential attackers for a vulnerability that could be exploited from across a network is larger than the number of potential attackers that could exploit a vulnerability requiring physical access to a device, and therefore warrants a greater severity.
Attack Complexity: This metric captures measurable actions that must be taken by the attacker to actively evade or circumvent existing built-in security-enhancing conditions in order to obtain a working exploit. These are conditions whose primary purpose is to increase security and/or increase exploit engineering complexity. A vulnerability exploitable without a target-specific variable has a lower complexity than a vulnerability that would require non-trivial customization. This metric is meant to capture security mechanisms utilized by the vulnerable system.
Attack Requirements: This metric captures the prerequisite deployment and execution conditions or variables of the vulnerable system that enable the attack. These differ from security-enhancing techniques/technologies (ref Attack Complexity) as the primary purpose of these conditions is not to explicitly mitigate attacks, but rather, emerge naturally as a consequence of the deployment and execution of the vulnerable system.
Privileges Required: This metric describes the level of privileges an attacker must possess prior to successfully exploiting the vulnerability. The method by which the attacker obtains privileged credentials prior to the attack (e.g., free trial accounts), is outside the scope of this metric. Generally, self-service provisioned accounts do not constitute a privilege requirement if the attacker can grant themselves privileges as part of the attack.
User interaction: This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable system. This metric determines whether the vulnerability can be exploited solely at the will of the attacker, or whether a separate user (or user-initiated process) must participate in some manner.
Vulnerable System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the VULNERABLE SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the VULNERABLE SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the VULNERABLE SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
Subsequent System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the SUBSEQUENT SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the SUBSEQUENT SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the SUBSEQUENT SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

EPSS score

0.043%
(10th percentile)

Weaknesses

CVE ID

CVE-2024-22032

GHSA ID

GHSA-q6c7-56cq-g2wm

Source code

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