{"cve":{"cve_id":"CVE-2021-1879","is_kev":true,"kev_date_added":"2021-11-03","kev_vendor_project":"Apple","kev_product":"iOS, iPadOS, and watchOS","kev_vulnerability_name":"Apple iOS, iPadOS, and watchOS WebKit Cross-Site Scripting (XSS) Vulnerability","kev_short_description":"Apple iOS, iPadOS, and watchOS WebKit contain an unspecified vulnerability that allows for universal cross-site scripting (XSS) when processing maliciously crafted web content. This vulnerability could impact HTML parsers that use WebKit, including but not limited to Apple Safari and non-Apple products which rely on WebKit for HTML processing.","kev_required_action":"Apply updates per vendor instructions.","kev_due_date":"2021-11-17","kev_known_ransomware":false,"kev_notes":"https://nvd.nist.gov/vuln/detail/CVE-2021-1879","kev_cwes":["CWE-79"],"epss_score":0.07082,"epss_percentile":0.93393,"epss_as_of":"2026-06-23","description":"This issue was addressed by improved management of object lifetimes. This issue is fixed in iOS 12.5.2, iOS 14.4.2 and iPadOS 14.4.2, watchOS 7.3.3. Processing maliciously crafted web content may lead to universal cross site scripting. Apple is aware of a report that this issue may have been actively exploited..","published_at":"2021-04-02T18:07:52Z","last_modified_at":null,"cvss_v3_score":6.1,"cvss_v3_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","cvss_v3_severity":"MEDIUM","cvss_v4_score":null,"cvss_v4_vector":null,"cvss_v4_severity":null,"ssvc_decision":null,"ssvc_exploitation":"active","ssvc_automatable":false,"ssvc_technical_impact":"partial","cwes":["CWE-79"],"nvd_references":["https://support.apple.com/en-us/HT212256","https://support.apple.com/en-us/HT212257","https://support.apple.com/en-us/HT212258"],"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":"2026-06-28T23:14:51.606149Z"},"effective_severity":"MEDIUM","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":"R","value_label":"Required"},{"metric":"S","name":"Scope","value":"C","value_label":"Changed"},{"metric":"C","name":"Confidentiality","value":"L","value_label":"Low"},{"metric":"I","name":"Integrity","value":"L","value_label":"Low"},{"metric":"A","name":"Availability","value":"N","value_label":"None"}]},"cvss_v4_decoded":{"version":null,"metrics":[]},"affected":[{"vendor_slug":"apple","vendor_name":"Apple","product_slug":"ios","product_name":"iOS","version_start":"unspecified","version_start_inclusive":true,"version_end":"12.5","version_end_inclusive":false,"cpe23_uri":"cve5:apple:ios:unspecified:12.5"},{"vendor_slug":"apple","vendor_name":"Apple","product_slug":"ios-and-ipados","product_name":"iOS and iPadOS","version_start":"unspecified","version_start_inclusive":true,"version_end":"14.4","version_end_inclusive":false,"cpe23_uri":"cve5:apple:ios-and-ipados:unspecified:14.4"},{"vendor_slug":"apple","vendor_name":"Apple","product_slug":"watchos","product_name":"watchOS","version_start":"unspecified","version_start_inclusive":true,"version_end":"7.3","version_end_inclusive":false,"cpe23_uri":"cve5:apple:watchos:unspecified:7.3"}],"exploit_refs":[],"news":[],"references":[{"url":"https://support.apple.com/en-us/HT212256","source_type":"VENDOR_ADVISORY","tags":["advisory"]},{"url":"https://support.apple.com/en-us/HT212257","source_type":"VENDOR_ADVISORY","tags":["advisory"]},{"url":"https://support.apple.com/en-us/HT212258","source_type":"VENDOR_ADVISORY","tags":["advisory"]}],"timeline":[{"type":"published","at":"2021-04-02T18:07:52Z","label":"CVE published","source":null},{"type":"cisa_reported","at":"2021-11-03T00:00:00Z","label":"Added to CISA KEV catalog","source":"kev"},{"type":"ssvc_changed","at":"2026-06-24T00:31:36.955378Z","label":"SSVC decision revised","source":"vulnrichment"},{"type":"ssvc_changed","at":"2026-06-24T00:31:36.955378Z","label":"SSVC decision revised","source":"vulnrichment"},{"type":"ssvc_changed","at":"2026-06-24T00:31:36.955378Z","label":"SSVC decision revised","source":"vulnrichment"},{"type":"cvss_changed","at":"2026-06-24T00:31:36.955378Z","label":"CVSS score revised","source":"vulnrichment"},{"type":"cvss_changed","at":"2026-06-24T00:31:36.955378Z","label":"CVSS score revised","source":"vulnrichment"},{"type":"cvss_changed","at":"2026-06-24T00:31:36.955378Z","label":"CVSS score revised","source":"vulnrichment"}]}