CVE-2025-27512: Zincati Zincati Allows Unprivileged Access To Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-w6fv-6gcc-x825",
  "modified" : "2025-03-19T15:00:20Z",
  "published" : "2025-03-17T14:46:56Z",
  "aliases" : [ "CVE-2025-27512" ],
  "summary" : "Zincati allows unprivileged access to rpm-ostree D-Bus `Deploy()` and `FinalizeDeployment()` methods",
  "details" : "### Impact\n\nZincati ships a polkit rule which allows the `zincati` system user to use the following actions:\n- `org.projectatomic.rpmostree1.deploy`: used to deploy updates to the system\n- `org.projectatomic.rpmostree1.finalize-deployment`: used to reboot the system into the deployed update\n\nSince Zincati [v0.0.24](https://github.com/coreos/zincati/releases/tag/v0.0.24), this polkit rule contains a logic error which broadens access of those polkit actions to any unprivileged user rather than just the `zincati` system user.\n\nIn practice, this means that any unprivileged user with access to the system D-Bus socket is able to deploy older Fedora CoreOS versions (which may have other known vulnerabilities). Note that rpm-ostree enforces that the selected version must be from the same branch the system is currently on so this cannot directly be used to deploy an attacker-controlled update payload.\n\nThis primarily impacts users running untrusted workloads with access to the system D-Bus socket. Note that in general, untrusted workloads should not be given this access, whether containerized or not. By default, containers do not have access to the system D-Bus socket.\n\n### Patches\n\nThe logic error is fixed in Zincati v0.0.30. The fix is included in the following FCOS releases:\n- On the `stable` stream: 41.20250302.3.2\n- On the `testing` stream: 41.20250315.2.0\n- On the `next` stream: 42.20250316.1.0\n\n### Workarounds\n\nA workaround is to add the following polkit rule:\n\n```javascript\npolkit.addRule(function(action, subject) {\n    if (action.id == \"org.projectatomic.rpmostree1.deploy\" ||\n        action.id == \"org.projectatomic.rpmostree1.finalize-deployment\" ||\n        action.id == \"org.projectatomic.rpmostree1.cleanup\") {\n        if (subject.user != \"zincati\") {\n                return polkit.Result.NO;\n        }\n    }\n});\n```\n\nto e.g. `/etc/polkit-1/rules.d/00-zincati-fix.rules` (it must sort earlier than `zincati.rules` lexicographically).\n\nNote that this rule will deny all non-root users other than `zincati` from using those actions. If you've added polkit rules to allow e.g. the `core` user or other users, you will need to adjust the policy (or make sure the ordering is appropriate).\n\n### References\n\nThis issue was introduced by [this commit](https://github.com/coreos/zincati/commit/28a43aa2c1edda091ba659677d73c13e6e3ea99d), and is fixed in [v0.0.30](https://github.com/coreos/zincati/releases/tag/v0.0.30).",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:U"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "zincati"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0.0.24"
      }, {
        "fixed" : "0.0.30"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 0.0.29"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/coreos/zincati/security/advisories/GHSA-w6fv-6gcc-x825"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-27512"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/coreos/zincati/commit/01d8e89f799e6ba21bdf7dc668abce23bd0d8f78"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/coreos/zincati/commit/28a43aa2c1edda091ba659677d73c13e6e3ea99d"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/coreos/zincati"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/coreos/zincati/releases/tag/v0.0.24"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/coreos/zincati/releases/tag/v0.0.30"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-783", "CWE-863" ],
    "severity" : "LOW",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-03-17T14:46:56Z",
    "nvd_published_at" : "2025-03-17T15:15:44Z"
  }
}