GHSA-RH99-WC69-C255
Vulnerability from github – Published: 2026-04-30 20:57 – Updated: 2026-04-30 20:57Impact
The Kata agent policies generated by the Contrast CLI had an issue in the CopyFile verification, which allowed arbitrary writes to the guest root filesytem. A malicious process on the host with the capability to connect to the Kata agent VSOCK could connect to the agent and issue a series of CopyFile requests to overwrite security-critical files or trick the workload into disclosing sensitive data, which effectively amounts to a full guest takeover.
Patches
This issue has been patched in Contrast v1.19.1.
Note that this fix does not change the fact that host-provided content is generally not trustworthy, as documented.
Workarounds
If upgrading is not possible, users can implement the fix in rego and pass it to contrast generate --policy. The rego-only fix is a bit trickier than the patch, because the data to check is binary. See the references for details.
Resources
- Upstream GHSA: https://github.com/kata-containers/kata-containers/security/advisories/GHSA-q49m-57vm-c8cc
- Alternative policy-only fix: https://gist.github.com/burgerdev/304dd0ab0fff1665b7c27e18a30cf96e
{
"affected": [
{
"package": {
"ecosystem": "Go",
"name": "github.com/edgelesssys/contrast"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "1.19.1"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [],
"database_specific": {
"cwe_ids": [
"CWE-59"
],
"github_reviewed": true,
"github_reviewed_at": "2026-04-30T20:57:17Z",
"nvd_published_at": null,
"severity": "HIGH"
},
"details": "### Impact\n\nThe [Kata agent policies](https://docs.edgeless.systems/contrast/architecture/components/policies) generated by the Contrast CLI had an issue in the `CopyFile` verification, which allowed arbitrary writes to the guest root filesytem. A malicious process on the host with the capability to connect to the Kata agent VSOCK could connect to the agent and issue a series of `CopyFile` requests to overwrite security-critical files or trick the workload into disclosing sensitive data, which effectively amounts to a full guest takeover.\n\n### Patches\n\nThis issue has been patched in Contrast v1.19.1.\n\nNote that this fix does not change the fact that host-provided content is generally not trustworthy, as documented.\n\n### Workarounds\n\nIf upgrading is not possible, users can implement the fix in rego and pass it to `contrast generate --policy`. The rego-only fix is a bit trickier than the patch, because the data to check is binary. See the references for details.\n\n### Resources\n\n* Upstream GHSA: https://github.com/kata-containers/kata-containers/security/advisories/GHSA-q49m-57vm-c8cc\n* Alternative policy-only fix: https://gist.github.com/burgerdev/304dd0ab0fff1665b7c27e18a30cf96e",
"id": "GHSA-rh99-wc69-c255",
"modified": "2026-04-30T20:57:17Z",
"published": "2026-04-30T20:57:17Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/edgelesssys/contrast/security/advisories/GHSA-rh99-wc69-c255"
},
{
"type": "WEB",
"url": "https://github.com/kata-containers/kata-containers/security/advisories/GHSA-q49m-57vm-c8cc"
},
{
"type": "WEB",
"url": "https://gist.github.com/burgerdev/304dd0ab0fff1665b7c27e18a30cf96e"
},
{
"type": "PACKAGE",
"url": "https://github.com/edgelesssys/contrast"
},
{
"type": "WEB",
"url": "https://github.com/edgelesssys/contrast/releases/tag/v1.19.1"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
"type": "CVSS_V3"
}
],
"summary": "Contras Affected by CopyFile Policy Subversion via Symlinks"
}
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