CVE-2023-30840 On a compromised node, the fluid-csi service account can be used to modify node specs
An attacker with node access can use the fluid-csi service account to modify node specs, escalating privileges to compromise the entire Kubernetes cluster.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2023-30840?
CVE-2023-30840 is a medium-severity vulnerability in fluid-cloudnative fluid, published on 8 May 2023. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
Fluid is an open source Kubernetes-native distributed dataset orchestrator and accelerator for data-intensive applications. Starting in version 0.7.0 and prior to version 0.8.6, if a malicious user gains control of a Kubernetes node running fluid csi pod (controlled by the `csi-nodeplugin-fluid` node-daemonset), they can leverage the fluid-csi service account to modify specs of all the nodes in the cluster. However, since this service account lacks `list node` permissions, the attacker may need to use other techniques to identify vulnerable nodes.
Once the attacker identifies and modifies the node specs, they can manipulate system-level-privileged components to access all secrets in the cluster or execute pods on other nodes. This allows them to elevate privileges beyond the compromised node and potentially gain full privileged access to the whole cluster.
To exploit this vulnerability, the attacker can make all other nodes unschedulable (for example, patch node with taints) and wait for system-critical components with high privilege to appear on the compromised node. However, this attack requires two prerequisites: a compromised node and identifying all vulnerable nodes through other means.
Version 0.8.6 contains a patch for this issue. As a workaround, delete the `csi-nodeplugin-fluid` daemonset in `fluid-system` namespace and avoid using CSI mode to mount FUSE file systems. Alternatively, using sidecar mode to mount FUSE file systems is recommended.
Weakness: CWE-863
Which versions are affected by CVE-2023-30840?
3 open source packages ship an affected version, including github.com/fluid-cloudnative/fluid. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/fluid-cloudnative/fluid Go | From 0.7.0 | 0.8.6 |
github.com/fluid-cloudnative/fluid Go | From 0.7.0 | 0.8.6 |
github.com/fluid-cloudnative/fluid Go | From 0.7.0 | 0.8.6 |
Products include Linuxfoundation Fluid.
How do I fix CVE-2023-30840?
Upgrade github.com/fluid-cloudnative/fluid to 0.8.6 or later.
Is CVE-2023-30840 being exploited?
There is no known exploitation of CVE-2023-30840 in the wild and no public exploit code.
Other vulnerabilities in fluid-cloudnative fluid
Sources
Also known as GHSA-93xx-cvmc-9w3v, GO-2023-1763.