Contrast vulnerability allows arbitrary host data Injection into container VOLUME mount pointsGHSA-phhq-63jg-fp7r
LOWFix: edgelesssys/contrast@635b471GHSA-phhq-63jg-fp7r is a low-severity (CVSS 3.5) CWE-693 vulnerability in github.com/edgelesssys/contrast. A fix is available for github.com/edgelesssys/contrast — see the affected versions and patch details below.
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-phhq-63jg-fp7r.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
github.com/edgelesssys/contrastReal-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
Background
The VOLUME directive in Dockerfiles, or the config.volumes field in OCI image descriptors, indicates filesystem paths "where the process is likely to write data". While these paths have special semantics in Docker, they are only hints in the OCI spec and are not treated specially by Kubernetes. However, containered implements the specified conversion logic and adds a mount point if there is none set by Kubernetes.
Unfortunately, the specification leaves it open whether the mount point is populated with any and what data, so the runtime needs to be able to push arbitrary data to the Kata agent. However, this is almost always not what the user wants:
- A declared
VOLUMElocation is usually important to the app's core functionality, which is usually at odds with the data in that location being untrusted. VOLUMEdeclarations are often used by image vendors to indicate "mount your persistence here" to the user. They are rarely useful without a real volume mounted there.
Impact
All of the following need to be true to be affected by this vulnerability:
- A bare metal Contrast deployment (AKS is not affected).
- An image with at least one VOLUME directive.
- No Kubernetes mount at the path of the VOLUME.
If these are all true, the host is able to write arbitrary trees below that mount point.
Patches
Patched in v1.9.1 by disallowing this configuration in contrast generate.
Workarounds
Explicitly mount an emptyDir to all VOLUME locations. If the initial data in these locations is needed by the application, the image needs to be modified to remove the config.volumes entries.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/edgelesssys/contrast | all versions | 1.9.1go get github.com/edgelesssys/contrast@v1.9.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/edgelesssys/contrast, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/edgelesssys/contrast to 1.9.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-phhq-63jg-fp7r 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.
Frequently Asked Questions
Is GHSA-phhq-63jg-fp7r in your dependencies?
Find it across Go, including transitive dependencies.