{
    "id": "CVE-2021-21249",
    "published": "2021-01-15 21:15:13",
    "last_modified": "2026-06-17 03:35:07",
    "cvss_score": "9.6",
    "cvss_severity": "CRITICAL",
    "cvss_version": "3.1",
    "cvss_vector": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N",
    "cwe": "CWE-74",
    "description": "OneDev is an all-in-one devops platform. In OneDev before version 4.0.3, there is an issue involving YAML parsing which can lead to post-auth remote code execution. In order to parse and process YAML files, OneDev uses SnakeYaml which by default (when not using `SafeConstructor`) allows the instantiation of arbitrary classes. We can leverage that to run arbitrary code by instantiating classes such as `javax.script.ScriptEngineManager` and using `URLClassLoader` to load the script engine provider, resulting in the instantiation of a user controlled class. For a full example refer to the referenced GHSA. This issue was addressed in 4.0.3 by only allowing certain known classes to be deserialized",
    "epss_score": "0.03059",
    "epss_percentile": "0.87239",
    "kev": 0,
    "kev_due": null,
    "has_exploit": 0,
    "updated_at": "2026-10-10 18:17:24",
    "priority": {
        "rank": 3,
        "label": "In your normal cycle",
        "why": "Critical by CVSS (9.6), but no sign of active exploitation."
    },
    "products": [
        {
            "vendor": "onedev_project",
            "product": "onedev"
        }
    ],
    "kev_detail": null,
    "exploits": [],
    "refs_list": [
        "https://github.com/theonedev/onedev/commit/d6fc4212b1ac1e9bbe3ce444e95f9af1e3ab8b66",
        "https://github.com/theonedev/onedev/security/advisories/GHSA-7xhq-m2q9-6hpm",
        "https://github.com/theonedev/onedev/commit/d6fc4212b1ac1e9bbe3ce444e95f9af1e3ab8b66",
        "https://github.com/theonedev/onedev/security/advisories/GHSA-7xhq-m2q9-6hpm"
    ]
}