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3.5

Cilium can crash node with certain annotations

CVE-2023-41332 · published 3 years ago
Summary

If you run Cilium without its Layer 7 proxy and add specific visibility annotations to a workload, the Cilium agent on that node can crash. The node will still handle existing traffic, but new workloads cannot start and changes cannot be applied, effectively blocking further activity on that node. Upgrade to Cilium 1.14.2, 1.13.7, or 1.12.14, or re‑enable the Layer 7 proxy to prevent this.

What to do
  • Update github.com cilium to version 1.14.2.
  • Update github.com cilium to version 1.12.14.
  • Update github.com cilium to version 1.13.7.
Affected software
Ecosystem VendorProductAffected versions
go github.com cilium >= 1.14.0, < 1.14.2
< 1.12.14
>= 1.13.0, < 1.13.7
Fix: upgrade to 1.14.2
– cilium cilium < 1.12.14
>= 1.13.0, < 1.13.7
>= 1.14.0, < 1.14.2
cpe:2.3:a:cilium:cilium:*:*:*:*:*:*:*:*
Original advisory text
Denial of service via Kubernetes annotations in specific Cilium configurations
Cilium is a networking, observability, and security solution with an eBPF-based dataplane. In Cilium clusters where Cilium's Layer 7 proxy has been disabled, creating workloads with `policy.cilium.io/proxy-visibility` annotations (in Cilium >= v1.13) or `io.cilium.proxy-visibility` annotations (in Cilium <= v1.12) causes the Cilium agent to segfault on the node to which the workload is assigned. Existing traffic on the affected node will continue to flow, but the Cilium agent on the node will not able to process changes to workloads running on the node. This will also prevent workloads from being able to start on the affected node. The denial of service will be limited to the node on which the workload is scheduled, however an attacker may be able to schedule workloads on the node of their choosing, which could lead to targeted attacks. This issue has been resolved in Cilium versions 1.14.2, 1.13.7, and 1.12.14. Users unable to upgrade can avoid this denial of service attack by enabling the Layer 7 proxy.

References
Fix within
Internet-facing 60 days
Internal At next upgrade
  • Not known to be exploited
  • Needs hands-on effort to exploit
  • Gives an attacker partial control
Severity
3.5 Low
Exploitation
<1% chance of attack within 30 days
Type
CWE-755Improper Handling of Exceptional Conditions
Timeline
Published26 Sep 2023
Updated4 Nov 2026
First seen6 Mar 2026
Sources
GHSA-24m5-r6hv-ccgp · GHSA
CVE-2023-41332 · NVD
CVE-2023-41332 · OSV
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