High severity · published Sep 13, 2022
CVE-2022-36103
Talos worker join token can be used to get elevated access level to the Talos API
8.8
CVSS
0.7%
EPSS
No
On KEV
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 vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.7% · higher than 53% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
TA
talos · siderolabs
< 1.2.2 · source: vendor
TL
Talos Linux · Siderolabs
before 1.2.2 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2022-36103
CVE.org
https://www.cve.org/CVERecord?id=CVE-2022-36103
Patch
https://github.com/siderolabs/talos/commit/9eaf33f3f274e746ca1b442c0a1a0dae0cec088f
Release Notes
https://github.com/siderolabs/talos/releases/tag/v1.2.2
Mitigation
https://github.com/siderolabs/talos/security/advisories/GHSA-7hgc-php5-77qq
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