{"cve":{"cve_id":"CVE-2021-27852","is_kev":true,"kev_date_added":"2022-04-11","kev_vendor_project":"Checkbox","kev_product":"Checkbox Survey","kev_vulnerability_name":"Checkbox Survey Deserialization of Untrusted Data Vulnerability","kev_short_description":"Deserialization of Untrusted Data vulnerability in CheckboxWeb.dll of Checkbox Survey allows an unauthenticated remote attacker to execute arbitrary code.","kev_required_action":"Versions 6 and earlier for this product are end-of-life and must be removed from agency networks. Versions 7 and later are not considered vulnerable.","kev_due_date":"2022-05-02","kev_known_ransomware":false,"kev_notes":"https://nvd.nist.gov/vuln/detail/CVE-2021-27852","kev_cwes":["CWE-502"],"epss_score":0.31946,"epss_percentile":0.98078,"epss_as_of":"2026-06-23","description":"Deserialization of Untrusted Data vulnerability in CheckboxWeb.dll of Checkbox Survey allows an unauthenticated remote attacker to execute arbitrary code. This issue affects: Checkbox Survey versions prior to 7.","published_at":"2021-05-27T20:55:11Z","last_modified_at":null,"cvss_v3_score":9.8,"cvss_v3_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cvss_v3_severity":"CRITICAL","cvss_v4_score":null,"cvss_v4_vector":null,"cvss_v4_severity":null,"ssvc_decision":null,"ssvc_exploitation":"active","ssvc_automatable":true,"ssvc_technical_impact":"total","cwes":["CWE-502"],"nvd_references":["https://www.kb.cert.org/vuls/id/706695"],"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":"2026-06-24T00:09:31.350578Z","updated_at":"2026-06-28T23:15:23.238880Z"},"effective_severity":"CRITICAL","badges":["kev"],"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":"N","value_label":"None"},{"metric":"UI","name":"User Interaction","value":"N","value_label":"None"},{"metric":"S","name":"Scope","value":"U","value_label":"Unchanged"},{"metric":"C","name":"Confidentiality","value":"H","value_label":"High"},{"metric":"I","name":"Integrity","value":"H","value_label":"High"},{"metric":"A","name":"Availability","value":"H","value_label":"High"}]},"cvss_v4_decoded":{"version":null,"metrics":[]},"affected":[{"vendor_slug":"checkbox","vendor_name":"Checkbox","product_slug":"survey","product_name":"Survey","version_start":"unspecified","version_start_inclusive":true,"version_end":"7","version_end_inclusive":false,"cpe23_uri":"cve5:checkbox:survey:unspecified:7"}],"exploit_refs":[],"news":[],"references":[{"url":"https://www.kb.cert.org/vuls/id/706695","source_type":"MISC","tags":[]}],"timeline":[{"type":"published","at":"2021-05-27T20:55:11Z","label":"CVE published","source":null},{"type":"cisa_reported","at":"2022-04-11T00:00:00Z","label":"Added to CISA KEV catalog","source":"kev"},{"type":"ssvc_changed","at":"2026-06-24T00:31:38.771468Z","label":"SSVC decision revised","source":"vulnrichment"},{"type":"ssvc_changed","at":"2026-06-24T00:31:38.771468Z","label":"SSVC decision revised","source":"vulnrichment"},{"type":"ssvc_changed","at":"2026-06-24T00:31:38.771468Z","label":"SSVC decision revised","source":"vulnrichment"},{"type":"cvss_changed","at":"2026-06-24T00:31:38.771468Z","label":"CVSS score revised","source":"vulnrichment"},{"type":"cvss_changed","at":"2026-06-24T00:31:38.771468Z","label":"CVSS score revised","source":"vulnrichment"},{"type":"cvss_changed","at":"2026-06-24T00:31:38.771468Z","label":"CVSS score revised","source":"vulnrichment"}]}