How severe is GHSA-c66w-hq56-4q97?

No CVSS score has been assigned to GHSA-c66w-hq56-4q97 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-c66w-hq56-4q97?

GHSA-c66w-hq56-4q97 affects the following packages: github.com/cilium/cilium (Go), github.com/cilium/cilium (Go), github.com/cilium/cilium (Go). Ecosystems affected: Go.

How do I fix GHSA-c66w-hq56-4q97?

Update github.com/cilium/cilium to 1.7.15 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-c66w-hq56-4q97 is resolved across your whole dependency graph.

How do I detect GHSA-c66w-hq56-4q97 in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/cilium/cilium. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate GHSA-c66w-hq56-4q97 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against GHSA-c66w-hq56-4q97?

O3 pinpoints whether GHSA-c66w-hq56-4q97 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-c66w-hq56-4q97 actively exploited in the wild?

No public exploit code has been indexed for GHSA-c66w-hq56-4q97 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

When was GHSA-c66w-hq56-4q97 published, and has it been updated?

GHSA-c66w-hq56-4q97 was published on May 21, 2021 and was last updated on August 21, 2024. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹 Go

Not in CISA KEV

GHSA-c66w-hq56-4q97

GHSA-c66w-hq56-4q97 is a security vulnerability in github.com/cilium/cilium. O3 Security confirms whether GHSA-c66w-hq56-4q97 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

Network policy may be bypassed by some ICMP Echo Requests

Also known asGO-2022-0393

Published

May 21, 2021

Updated

Aug 21, 2024

Affected

3 pkgs

Patched

3 / 3

Exploits

None indexed

Exploitation data as of Aug 21, 2024 · OSV.dev, FIRST.org (EPSS)

Real-World Exposure

3 pkgs affected

🐹github.com/cilium/cilium🐹github.com/cilium/cilium🐹github.com/cilium/cilium

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

Impact

Under certain conditions, ICMP Echo Request sent to a Cilium endpoint from an actor may bypass a network policy which disallows access from the actor to the endpoint, but allows from the endpoint to the actor. This does NOT apply to UDP and TCP traffic.

The actor is either a pod or a cluster host or a remote host.

The following conditions must be met:

Network policies have been created which: a) do not allow access from the actor to the endpoint; b) allow access from the endpoint to the actor and does not specify neither protocol nor port.
The endpoint has sent ICMP Echo Request to the actor with the ICMP identifier X.
The actor sends ICMP Echo Request to the endpoint with the same ICMP identifier X.
The request from the actor (3.) is sent before the Cilium's conntrack GC has removed the previously created conntrack entry (2.).

Detailed description

See https://github.com/cilium/cilium/commit/dfb008a9099c4da1e0fd964c899c43ee13280b0e (v1.9.x), https://github.com/cilium/cilium/commit/ff6ebae6efca1bd991302b464dea428512823e79 (v1.8.x), https://github.com/cilium/cilium/commit/472bbeff75161979c317ab21d563f826291b5f37 (v1.7.x).

Example

$ kubectl run server --image=quay.io/cilium/net-test:v1.0.0 --restart=Never -- sleep 3600
$ kubectl run client --image=quay.io/cilium/net-test:v1.0.0 --restart=Never -- sleep 3600
$ cat <<EOF | kubectl apply -f
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: server-netpol # allow client->server
spec:
  podSelector:
    matchLabels:
      run: server
  ingress:
  - from:
    - podSelector:
        matchLabels:
          run: client
  policyTypes:
  - Ingress
---
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: client-netpol # deny any->client
spec:
  podSelector:
    matchLabels:
      run: client
  policyTypes:
  - Ingress
EOF

$ kubectl exec -ti server -- xping -c1 -x666 $CLIENT_POD_IP
PING 10.154.0.50 (10.154.0.50): 56 data bytes
^C
--- 10.154.0.50 ping statistics ---
1 packets transmitted, 0 packets received, 100% packet loss   <--- "client-netpol" policy denied
command terminated with exit code 1

$ kubectl exec -ti client -- xping -c1 -x666 $SERVER_POD_IP
PING 10.154.1.16 (10.154.1.16): 56 data bytes
64 bytes from 10.154.1.16: seq=0 ttl=60 time=0.822 ms

--- 10.154.1.16 ping statistics ---
1 packets transmitted, 1 packets received, 0% packet loss   <--- "server-netpol" policy allowed
round-trip min/avg/max = 0.822/0.822/0.822 ms

$ kubectl exec -ti server -- xping -c1 -x666 $CLIENT_POD_IP
PING 10.154.0.50 (10.154.0.50): 56 data bytes
64 bytes from 10.154.0.50: seq=0 ttl=60 time=0.527 ms

--- 10.154.0.50 ping statistics ---
1 packets transmitted, 1 packets received, 0% packet loss   <--- "client-netpol" policy bypassed
round-trip min/avg/max = 0.527/0.527/0.527 ms

For more information

If you have any questions or comments about this advisory:

Open an issue in Cilium Issues
Email us at [email protected]

Affected Packages

3 total 3 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/cilium/cilium`	≥ 1.7.8&&< 1.7.15	1.7.15
🐹Go	`github.com/cilium/cilium`	≥ 1.8.3&&< 1.8.8	1.8.8
🐹Go	`github.com/cilium/cilium`	≥ 1.9.0&&< 1.9.5	1.9.5

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/cilium/cilium. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/cilium/cilium to 1.7.15 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-c66w-hq56-4q97 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-c66w-hq56-4q97 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-c66w-hq56-4q97. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

## Impact Under certain conditions, ICMP Echo Request sent to a Cilium endpoint from an actor may bypass a network policy which _disallows_ access from the actor to the endpoint, but _allows_ from the endpoint to the actor. This does _NOT_ apply to UDP and TCP traffic. The actor is either a pod or a cluster host or a remote host. The following conditions must be met: 1. Network policies have been created which: a) do not allow access from the actor to the endpoint; b) allow access from the endpoint to the actor and does not specify neither protocol nor port. 2. The endpoint has sent IC

O3 Security · Impact-Aware SCA

Is GHSA-c66w-hq56-4q97 in your dependencies?

O3 detects GHSA-c66w-hq56-4q97 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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