CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS
Percentile
20.0%
The external-secrets has a deployment called default-external-secrets-cert-controller, which is bound with a same-name ClusterRole. This ClusterRole has “get/list” verbs of secrets resources(https://github.com/external-secrets/external-secrets/blob/main/deploy/charts/external-secrets/templates/cert-controller-rbac.yaml#L49). It also has path/update verb of validatingwebhookconfigurations resources(https://github.com/external-secrets/external-secrets/blob/main/deploy/charts/external-secrets/templates/cert-controller-rbac.yaml#L27). As a result, if a malicious user can access the worker node which has this deployment. he/she can:
For the “get/list secrets” permission, he/she can abuse the SA token of this deployment to retrieve or get ALL secrets in the whole cluster, including the cluster-admin secret if created. After that, he/she can abuse the cluster-admin secret to do whatever he/she likes to the whole cluster, resulting in a cluster-level privilege escalation.
For the patch/update verb of validatingwebhookconfigurations, the malicious user can abuse these permissions to get sensitive data or lanuch DoS attacks:
For the privilege escalation attack, by updating/patching a Webhook to make it listen to Secret update operations, the attacker can capture and log all data from requests attempting to update Secrets. More specifically, when a Secret is updated, this Webhook sends the request data to the logging-service, which can then log the content of the Secret. This way, an attacker could indirectly gain access to the full contents of the Secret.
For the DoS attack, by updating/patching a Webhook, and making it deny all Pod create and update requests, the attacker can prevent any new Pods from being created or existing Pods from being updated, resulting in a Denial of Service (DoS) attack.
Please see the “Details” section
Privilege escalation
github.com/external-secrets/external-secrets
github.com/external-secrets/external-secrets/blob/main/deploy/charts/external-secrets/templates/cert-controller-rbac.yaml#L27
github.com/external-secrets/external-secrets/blob/main/deploy/charts/external-secrets/templates/cert-controller-rbac.yaml#L49
github.com/external-secrets/external-secrets/commit/0368b9806f660fa6bc52cbbf3c6ccdb27c58bb35
github.com/external-secrets/external-secrets/commit/428a452fd2ad45935312f2c2c0d40bc37ce6e67c
github.com/external-secrets/external-secrets/security/advisories/GHSA-qwgc-rr35-h4x9
nvd.nist.gov/vuln/detail/CVE-2024-45041
pkg.go.dev/vuln/GO-2024-3126