Cilium is a networking, observability, and security solution with an eBPF-based dataplane. Prior to versions 1.14.14 and 1.15.8, a race condition in the Cilium agent can cause the agent to ignore labels that should be applied to a node. This could in turn cause CiliumClusterwideNetworkPolicies intended for nodes with the ignored label to not apply, leading to policy bypass. This issue has been patched in Cilium v1.14.14 and v1.15.8 As the underlying issue depends on a race condition, users unable to upgrade can restart the Cilium agent on affected nodes until the affected policies are confirmed to be working as expected.
The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Cilium | Cilium | * | 1.14.14 (excluding) |
| Cilium | Cilium | 1.15.0 (including) | 1.15.8 (excluding) |
A race condition occurs within concurrent environments, and it is effectively a property of a code sequence. Depending on the context, a code sequence may be in the form of a function call, a small number of instructions, a series of program invocations, etc. A race condition violates these properties, which are closely related:
A race condition exists when an “interfering code sequence” can still access the shared resource, violating exclusivity. The interfering code sequence could be “trusted” or “untrusted.” A trusted interfering code sequence occurs within the product; it cannot be modified by the attacker, and it can only be invoked indirectly. An untrusted interfering code sequence can be authored directly by the attacker, and typically it is external to the vulnerable product.