CVE-2024-47825

Cilium is a networking, observability, and security solution with an eBPF-based dataplane. Starting in version 1.14.0 and prior to versions 1.14.16 and 1.15.10, a policy rule denying a prefix that is broader than /32 may be ignored if there is a policy rule referencing a more narrow prefix (CIDRSet or toFQDN) and this narrower policy rule specifies either enableDefaultDeny: false or - toEntities: all. Note that a rule specifying toEntities: world or toEntities: 0.0.0.0/0 is insufficient, it must be to entity all.This issue has been patched in Cilium v1.14.16 and v1.15.10. As this issue only affects policies using enableDefaultDeny: false or that set toEntities to all, some workarounds are available. For users with policies using enableDefaultDeny: false, remove this configuration option and explicitly define any allow rules required. For users with egress policies that explicitly specify toEntities: all, use toEntities: world.

Weakness

During installation, installed file permissions are set to allow anyone to modify those files.

Potential Mitigations

• Compartmentalize the system to have “safe” areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
• Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/1.html
• https://cwe.mitre.org/data/definitions/127.html
• https://cwe.mitre.org/data/definitions/81.html

References

• https://github.com/cilium/cilium/security/advisories/GHSA-3wwx-63fv-pfq6