kubeclient: Improper Certificate Validation
CVE-2022-0759 is a high-severity improper certificate validation vulnerability in kubeclient, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected kubeclient versions: 4.9.3. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.94% chance of exploitation within 30 days, higher than 62% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of kubeclient you run against the affected versions below, and install the vendor's latest release.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Kubeclient | kubeclient | 4.9.3 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- HighSuccess depends on conditions outside the attacker's control.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.1 | High | NVD |
| CVSS 2.0 | 6.8 | Medium | NVD |
Official description
A flaw was found in all versions of kubeclient up to (but not including) v4.9.3, the Ruby client for Kubernetes REST API, in the way it parsed kubeconfig files. When the kubeconfig file does not configure custom CA to verify certs, kubeclient ends up accepting any certificate (it wrongly returns VERIFY_NONE). Ruby applications that leverage kubeclient to parse kubeconfig files are susceptible to Man-in-the-middle attacks (MITM).
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Certificate Validation
The product does not validate, or incorrectly validates, a certificate.
How developers prevent this class of flaw
- Certificates should be carefully managed and checked to assure that data are encrypted with the intended owner's public key.
- If certificate pinning is being used, ensure that all relevant properties of the certificate are fully validated before the certificate is pinned, including the hostname.
More Improper Certificate Validation vulnerabilities (CWE-295)
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- github.com/ManageIQ/kubeclient/issues/554Issue Tracking, Third Party Advisory
- github.com/ManageIQ/kubeclient/issues/555Issue Tracking, Third Party Advisory
Recent Improper Certificate Validation vulnerabilities
- 7.5 High severity
- 9.8 Critical severity
- 7.5 High severity
- 8.0 High severity
- 7.4 High severity
- 8.1 High severity
Microsoft Windows CryptoAPI Spoofing Exploited
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