GHSA-fcm2-6c3h-pg6j
HIGHNode DOS by way of memory exhaustion through ExecSync request in CRI-O
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
github.com/cri-o/cri-o🐹github.com/cri-o/cri-o🐹github.com/cri-o/cri-oReal-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
Description
An ExecSync request runs a command in a container and returns the output to the Kubelet. It is used for readiness and liveness probes within a pod. The way CRI-O runs ExecSync commands is through conmon. CRI-O asks conmon to start the process, and conmon writes the output to disk. CRI-O then reads the output and returns it to the Kubelet.
If the output of the command is large enough, it is possible to exhaust the memory (or disk usage) of the node. The following deployment is an example yaml file that will output around 8GB of ‘A’ characters, which would be written to disk by conmon and read by CRI-O.
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx-deployment100
spec:
selector:
matchLabels:
app: nginx
replicas: 2
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx:1.14.2
lifecycle:
postStart:
exec:
command: ["/bin/sh", "-c", "seq 1 50000000`; do echo -n 'aaaaaaaaaaaaaaaa'; done"]
Impact
It is possible for the node to be exhausted of memory or disk space, depending on the node the command is being run on. What is further problematic is that the memory and disk usage aren't attributed to the container, as this file and its processing are implementation details of CRI-O. The consequence of the exhaustion is that other services on the node, e.g. other containers, will be unable to allocate memory and thus causing a denial of service.
Patches
This vulnerability will be fixed in 1.24.1, 1.23.3, 1.22.5, v1.21.8, v1.20.8, v1.19.7
Workarounds
At the time of writing, no workaround exists other than ensuring only trusted images are used.
References
https://github.com/containerd/containerd/security/advisories/GHSA-5ffw-gxpp-mxpf
For more information
If you have any questions or comments about this advisory:
- Open an issue in the CRI-O repo
- To make a report, email your vulnerability to the private [email protected] list with the security details and the details expected for all CRI-O bug reports.
Credits
Disclosed by Ada Logics in a security audit sponsored by CNCF and facilitated by OSTIF.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/cri-o/cri-o | ≥ 1.24.0&&< 1.24.1 | 1.24.1 |
| 🐹Go | github.com/cri-o/cri-o | ≥ 1.23.0&&< 1.23.3 | 1.23.3 |
| 🐹Go | github.com/cri-o/cri-o | all versions | 1.22.5 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/cri-o/cri-o. 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/cri-o/cri-o to 1.24.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-fcm2-6c3h-pg6j 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-fcm2-6c3h-pg6j 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-fcm2-6c3h-pg6j. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-fcm2-6c3h-pg6j in your dependencies?
O3 detects GHSA-fcm2-6c3h-pg6j across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.