GHSA-PHHQ-63JG-FP7R
Vulnerability from github – Published: 2025-07-09 17:56 – Updated: 2025-07-09 17:56Background
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": [
{
"package": {
"ecosystem": "Go",
"name": "github.com/edgelesssys/contrast"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "1.9.1"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [],
"database_specific": {
"cwe_ids": [
"CWE-552",
"CWE-693"
],
"github_reviewed": true,
"github_reviewed_at": "2025-07-09T17:56:24Z",
"nvd_published_at": null,
"severity": "LOW"
},
"details": "### Background\n\nThe [`VOLUME`](https://docs.docker.com/reference/dockerfile/#volume) directive in Dockerfiles, or the [`config.volumes`](https://github.com/opencontainers/image-spec/blob/06e6b47e2ef69021d9f9bf2cfa5fe43a7e010c81/config.md?plain=1#L168-L170) 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](https://github.com/opencontainers/image-spec/blob/06e6b47e2ef69021d9f9bf2cfa5fe43a7e010c81/conversion.md?plain=1#L100-L105) and adds a mount point if there is none set by Kubernetes.\n\nUnfortunately, 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:\n\n1. A declared `VOLUME` location is usually important to the app\u0027s core functionality, which is usually at odds with the data in that location being untrusted.\n2. `VOLUME` declarations 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.\n\n### Impact\n\nAll of the following need to be true to be affected by this vulnerability:\n\n1. A bare metal Contrast deployment (AKS is not affected).\n2. An image with at least one VOLUME directive.\n3. No Kubernetes mount at the path of the VOLUME.\n\nIf these are all true, the host is able to write arbitrary trees below that mount point.\n\n### Patches\n\nPatched in v1.9.1 by disallowing this configuration in `contrast generate`.\n\n### Workarounds\n\nExplicitly 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.",
"id": "GHSA-phhq-63jg-fp7r",
"modified": "2025-07-09T17:56:24Z",
"published": "2025-07-09T17:56:24Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/edgelesssys/contrast/security/advisories/GHSA-phhq-63jg-fp7r"
},
{
"type": "WEB",
"url": "https://github.com/edgelesssys/contrast/commit/635b471ddbb512b6661e6f1d767aab818bd50bda"
},
{
"type": "PACKAGE",
"url": "https://github.com/edgelesssys/contrast"
},
{
"type": "WEB",
"url": "https://github.com/edgelesssys/contrast/releases/tag/v1.9.1"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N",
"type": "CVSS_V3"
}
],
"summary": "Contrast vulnerability allows arbitrary host data Injection into container VOLUME mount points"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.