{"cve":{"cve_id":"CVE-2021-21249","is_kev":false,"kev_date_added":null,"kev_vendor_project":null,"kev_product":null,"kev_vulnerability_name":null,"kev_short_description":null,"kev_required_action":null,"kev_due_date":null,"kev_known_ransomware":null,"kev_notes":null,"kev_cwes":null,"epss_score":0.02932,"epss_percentile":0.85292,"epss_as_of":"2026-06-23","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","published_at":"2021-01-15T20:10:31Z","last_modified_at":null,"cvss_v3_score":9.6,"cvss_v3_vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N","cvss_v3_severity":"CRITICAL","cvss_v4_score":null,"cvss_v4_vector":null,"cvss_v4_severity":null,"ssvc_decision":null,"ssvc_exploitation":null,"ssvc_automatable":null,"ssvc_technical_impact":null,"cwes":["CWE-74"],"nvd_references":["https://github.com/theonedev/onedev/security/advisories/GHSA-7xhq-m2q9-6hpm","https://github.com/theonedev/onedev/commit/d6fc4212b1ac1e9bbe3ce444e95f9af1e3ab8b66"],"vuln_status":null,"trending_score":null,"is_trending":false,"has_trended":false,"trended_number_one":false,"trending_peak_score":null,"trending_peak_rank":null,"started_trending_at":null,"trended_number_one_at":null,"summary_generated":null,"summary_generated_at":null,"summary_model":null,"created_at":"2026-06-24T00:09:39.878444Z","updated_at":"2026-06-28T23:14:57.081228Z"},"effective_severity":"CRITICAL","badges":[],"impact_analysis":[],"cvss_v3_decoded":{"version":"3.1","metrics":[{"metric":"AV","name":"Attack Vector","value":"N","value_label":"Network"},{"metric":"AC","name":"Attack Complexity","value":"L","value_label":"Low"},{"metric":"PR","name":"Privileges Required","value":"L","value_label":"Low"},{"metric":"UI","name":"User Interaction","value":"N","value_label":"None"},{"metric":"S","name":"Scope","value":"C","value_label":"Changed"},{"metric":"C","name":"Confidentiality","value":"H","value_label":"High"},{"metric":"I","name":"Integrity","value":"H","value_label":"High"},{"metric":"A","name":"Availability","value":"N","value_label":"None"}]},"cvss_v4_decoded":{"version":null,"metrics":[]},"affected":[{"vendor_slug":"theonedev","vendor_name":"theonedev","product_slug":"onedev","product_name":"onedev","version_start":"< 4.0.3","version_start_inclusive":true,"version_end":"< 4.0.3","version_end_inclusive":true,"cpe23_uri":"cve5:theonedev:onedev:< 4.0.3:< 4.0.3"}],"exploit_refs":[],"news":[],"references":[{"url":"https://github.com/theonedev/onedev/security/advisories/GHSA-7xhq-m2q9-6hpm","source_type":"VENDOR_ADVISORY","tags":["advisory"]},{"url":"https://github.com/theonedev/onedev/commit/d6fc4212b1ac1e9bbe3ce444e95f9af1e3ab8b66","source_type":"PATCH","tags":["patch"]}],"timeline":[{"type":"published","at":"2021-01-15T20:10:31Z","label":"CVE published","source":null},{"type":"cvss_changed","at":"2026-06-28T17:05:11.212102Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:05:11.212102Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:05:11.212102Z","label":"CVSS score revised","source":"cvelistv5"}]}