CVE Vulnerabilities

CVE-2020-11013

Exposure of Sensitive Information to an Unauthorized Actor

Published: Apr 24, 2020 | Modified: Jul 06, 2020
CVSS 3.x
5
MEDIUM
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N
CVSS 2.x
4 MEDIUM
AV:N/AC:L/Au:S/C:P/I:N/A:N
RedHat/V2
RedHat/V3
Ubuntu

Their is an information disclosure vulnerability in Helm from version 3.1.0 and before version 3.2.0. lookup is a Helm template function introduced in Helm v3. It is able to lookup resources in the cluster to check for the existence of specific resources and get details about them. This can be used as part of the process to render templates. The documented behavior of helm template states that it does not attach to a remote cluster. However, a the recently added lookup template function circumvents this restriction and connects to the cluster even during helm template and helm install|update|delete|rollback --dry-run. The user is not notified of this behavior. Running helm template should not make calls to a cluster. This is different from install, which is presumed to have access to a cluster in order to load resources into Kubernetes. Helm 2 is unaffected by this vulnerability. A malicious chart author could inject a lookup into a chart that, when rendered through helm template, performs unannounced lookups against the cluster a user's KUBECONFIG file points to. This information can then be disclosed via the output of helm template. This issue has been fixed in Helm 3.2.0

Weakness

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

Affected Software

Name Vendor Start Version End Version
Helm Helm 3.1.0 (including) 3.2.0 (excluding)

Extended Description

There are many different kinds of mistakes that introduce information exposures. The severity of the error can range widely, depending on the context in which the product operates, the type of sensitive information that is revealed, and the benefits it may provide to an attacker. Some kinds of sensitive information include:

Information might be sensitive to different parties, each of which may have their own expectations for whether the information should be protected. These parties include:

Information exposures can occur in different ways:

It is common practice to describe any loss of confidentiality as an “information exposure,” but this can lead to overuse of CWE-200 in CWE mapping. From the CWE perspective, loss of confidentiality is a technical impact that can arise from dozens of different weaknesses, such as insecure file permissions or out-of-bounds read. CWE-200 and its lower-level descendants are intended to cover the mistakes that occur in behaviors that explicitly manage, store, transfer, or cleanse sensitive information.

Potential Mitigations

  • 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.

References