CVE-2022-36103
Due to improper validation of the request while signing a worker node CSR (certificate signing request) Talos control plane node might issue Talos API certificate which allows full access to Talos API on a control plane node.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.68%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Talos Linux is a Linux distribution built for Kubernetes deployments. Talos worker nodes use a join token to get accepted into the Talos cluster. Due to improper validation of the request while signing a worker node CSR (certificate signing request) Talos control plane node might issue Talos API certificate which allows full access to Talos API on a control plane node. Accessing Talos API with full level access on a control plane node might reveal sensitive information which allows full level access to the cluster (Kubernetes and Talos PKI, etc.). Talos API join token is stored in the machine configuration on the worker node. When configured correctly, Kubernetes workloads don't have access to the machine configuration, but due to a misconfiguration workload might access the machine configuration and reveal the join token. This problem has been fixed in Talos 1.2.2. Enabling the Pod Security Standards mitigates the vulnerability by denying hostPath mounts and host networking by default in the baseline policy. Clusters that don't run untrusted workloads are not affected. Clusters with correct Pod Security configurations which don't allow hostPath mounts, and secure access to cloud metadata server (or machine configuration is not supplied via cloud metadata server) are not affected.
- CVSS 3.1
- 8.8 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.68% probability · 50th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-732, CWE-863
- Affected
- siderolabs/talos linux
- Source
- security-advisories@github.com
References
- https://github.com/siderolabs/talos/commit/9eaf33f3f274e746ca1b442c0a1a0dae0cec088fPatch, Third Party Advisory
- https://github.com/siderolabs/talos/releases/tag/v1.2.2Release Notes, Third Party Advisory
- https://github.com/siderolabs/talos/security/advisories/GHSA-7hgc-php5-77qqMitigation, Third Party Advisory
- https://github.com/siderolabs/talos/commit/9eaf33f3f274e746ca1b442c0a1a0dae0cec088fPatch, Third Party Advisory
- https://github.com/siderolabs/talos/releases/tag/v1.2.2Release Notes, Third Party Advisory
- https://github.com/siderolabs/talos/security/advisories/GHSA-7hgc-php5-77qqMitigation, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.