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GHSA-cq4p-vp5q-4522 CVE-2022-43757

Plaintext storage of sensitive data in Rancher API and cluster.management.cattle.io objects

High Go
Severity
8.8 / 10
High · CVSS 3.1
Exploit chance (EPSS)
0.55%
Chance of exploitation in the next 30 days. Higher than 46.19% of scored vulnerabilities.
Known exploited
No
Not in CISA's catalog
Weakness
CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
CWE-256 Plaintext Storage of a Password
CWE-312 Cleartext Storage of Sensitive Information
Fix
2.5.17
Upgrade github.com/rancher/rancher to this version or later

Description

Impact

This issue affects Rancher versions from 2.5.0 up to and including 2.5.16, from 2.6.0 up to and including 2.6.9 and 2.7.0. It was discovered that the security advisory CVE-2021-36782 (GHSA-g7j7-h4q8-8w2f), previously released by Rancher, missed addressing some sensitive fields, secret tokens, encryption keys, and SSH keys that were still being stored in plaintext directly on Kubernetes objects like Clusters.

The exposed credentials are visible in Rancher to authenticated Cluster Owners, Cluster Members, Project Owners and Project Members of that cluster on the endpoints:

  • /v1/management.cattle.io.cluster
  • /v1/management.cattle.io.clustertemplaterevisions

The remaining sensitive fields are now stripped from Clusters and other objects and moved to a Secret before the object is stored. The Secret is retrieved when the credential is needed. For objects that existed before this security fix, a one-time migration happens on startup.

The fields that have been addressed by this security fix are:

  • Cluster.Spec.RancherKubernetesEngineConfig.Services.KubeAPI.SecretsEncryptionConfig.CustomConfig.Providers[].AESGCM.Keys[].Secret
  • Cluster.Spec.RancherKubernetesEngineConfig.Services.KubeAPI.SecretsEncryptionConfig.CustomConfig.Providers[].AESCBC.Keys[].Secret
  • Cluster.Spec.RancherKubernetesEngineConfig.Services.KubeAPI.SecretsEncryptionConfig.CustomConfig.Providers[].SecretboxConfiguration.Keys[].Secret
  • Cluster.Spec.RancherKubernetesEngineConfig.Services.Kubelet.ExtraEnv when containing the AWS_SECRET_ACCESS_KEY environment variable
  • Cluster.Spec.RancherKubernetesEngineConfig.BastionHost.SSHKey
  • Cluster.Spec.RancherKubernetesEngineConfig.PrivateRegistries[].ECRCredentialPlugin.AwsSecretAccessKey
  • Cluster.Spec.RancherKubernetesEngineConfig.PrivateRegistries[].ECRCredentialPlugin.AwsSessionToken
  • Cluster.Spec.RancherKubernetesEngineConfig.Network.AciNetworkProvider.ApicUserKey
  • Cluster.Spec.RancherKubernetesEngineConfig.Network.AciNetworkProvider.KafkaClientKey
  • Cluster.Spec.RancherKubernetesEngineConfig.Network.AciNetworkProvider.Token

Important:

  • For the exposure of credentials not related to Rancher, the final impact severity for confidentiality, integrity and availability is dependent on the permissions the leaked credentials have on their services.

  • It is recommended to review for potentially leaked credentials in this scenario and to change them if deemed necessary.

Workarounds

There is no direct mitigation besides updating Rancher to a patched version.

Patches

Patched versions include releases 2.5.17, 2.6.10, 2.7.1 and later versions.

After upgrading to a patched version, it is important to check for the ACISecretsMigrated and RKESecretsMigrated conditions on Clusters and ClusterTemplateRevisions to confirm when secrets have been fully migrated off of those objects, and the objects scoped within them.

For more information

If you have any questions or comments about this advisory:

Affected versions

Go

PackageVulnerableFixed in
github.com/rancher/rancher
>= 2.5.0, < 2.5.17
2.5.17
github.com/rancher/rancher
>= 2.6.0, < 2.6.10
2.6.10
github.com/rancher/rancher
>= 2.7.0, < 2.7.1
2.7.1

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

github.com/rancher/rancher Go → 2.5.17

go
go get github.com/rancher/rancher@v2.5.17 && go mod tidy

Severity breakdown

CVSS 3.1 8.8

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Weakness

CWE-200: Exposure of Sensitive Information to an Unauthorized Actor

The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.

How to prevent it
  • Architecture and Design: Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.

CWE-256: Plaintext Storage of a Password

The product stores a password in plaintext within resources such as memory or files.

How to prevent it
  • Architecture and Design: Avoid storing passwords in easily accessible locations.
  • Architecture and Design: Consider storing cryptographic hashes of passwords as an alternative to storing in plaintext.
  • A programmer might attempt to remedy the password management problem by obscuring the password with an encoding function, such as base 64 encoding, but this effort does not adequately protect the password because the encoding can be detected and decoded easily.

CWE-312: Cleartext Storage of Sensitive Information

The product stores sensitive information in cleartext within a resource that might be accessible to another control sphere.

How to prevent it
  • Implementation, System Configuration, Operation: When storing data in the cloud (e.g., S3 buckets, Azure blobs, Google Cloud Storage, etc.), use the provider's controls to encrypt the data at rest. [REF-1297] [REF-1299] [REF-1301]
  • Implementation, System Configuration, Operation: In some systems/environments such as cloud, the use of "double encryption" (at both the software and hardware layer) might be required, and the developer might be solely responsible for both layers, instead of shared responsibility with the administrator of the broader system/environment.

References

Timeline

  1. Published
  2. Last updated by the source
  3. Latest EPSS score
AdvisorySeverityWhy it's related
GHSA-4j6x-2764-m8gh
Rancher has over-inclusive team membership expansion in GitHub App authentication provider
High Also affects github.com/rancher/rancher
GHSA-vx8h-4prv-g744
Rancher has Privilege Escalation from Project Owner to Host
High Also affects github.com/rancher/rancher
GHSA-mhc6-2gfq-xx62
Rancher vulnerable to command injection through unsanitized YAML parameter
Critical Also affects github.com/rancher/rancher
GHSA-5v3h-x4wf-5c35
Rancher Extensions have arbitrary file access via path traversal
High Also affects github.com/rancher/rancher
GHSA-gqf8-rvrh-g7w6
Rancher cloud credentials can be used through proxy API by users without access
Critical Also affects github.com/rancher/rancher
GHSA-hwm2-4ph6-w6m5
Rancher's restricted PodSecurityPolicy does not prevent containers from running as a privileged user
High Also affects github.com/rancher/rancher
GHSA-mc24-7m59-4q5p
Rancher CLI skips TLS verification on Rancher CLI login command
Medium Also affects github.com/rancher/rancher
GHSA-mw39-9qc2-f7mg
Rancher exposes sensitive information through audit logs
Medium Also affects github.com/rancher/rancher
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