{"id":"CVE-2025-27512","aliases":["GHSA-w6fv-6gcc-x825"],"url":"https://o3.security/vulnerability/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).","published":"2025-03-17T14:46:28.219Z","modified":"2026-08-12T03:51:23.592520453Z","cvss":null,"epss":{"score":0.00182,"percentile":0.07814,"asOf":"2026-08-24"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"crates.io","name":"zincati","fixedVersion":"0.0.30"}],"fix":{"url":"https://github.com/coreos/zincati/commit/01d8e89f799e6ba21bdf7dc668abce23bd0d8f78","label":"coreos/zincati@01d8e89"},"references":[{"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"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/27xxx/CVE-2025-27512.json"},{"type":"ADVISORY","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":"FIX","url":"https://github.com/coreos/zincati/commit/01d8e89f799e6ba21bdf7dc668abce23bd0d8f78"},{"type":"FIX","url":"https://github.com/coreos/zincati/commit/28a43aa2c1edda091ba659677d73c13e6e3ea99d"},{"type":"PACKAGE","url":"https://github.com/coreos/zincati"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:23.592520453Z"}}