{
  "id": "CVE-2021-1879",
  "url": "https://spydr.io/cve/CVE-2021-1879",
  "published": "2021-04-02T19:15:20.770Z",
  "modified": "2026-06-17T03:32:42.883Z",
  "score": 6.1,
  "severity": "medium",
  "cvss_version": "3.1",
  "vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
  "score_source": "NVD",
  "epss": 0.07082,
  "epss_percentile": 0.94061,
  "exploited": true,
  "kev": {
    "added": "2021-11-03",
    "due": "2021-11-17",
    "action": "Apply updates per vendor instructions.",
    "ransomware": "Unknown",
    "name": "Apple iOS, iPadOS, and watchOS WebKit Cross-Site Scripting (XSS) Vulnerability",
    "notes": "https://nvd.nist.gov/vuln/detail/CVE-2021-1879"
  },
  "ssvc_exploitation": "active",
  "vendors": [
    "Apple"
  ],
  "products": [
    "Apple iOS and iPadOS",
    "Apple iOS",
    "Apple watchOS"
  ],
  "cwes": [
    "CWE-79"
  ],
  "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..",
  "status": "Analyzed",
  "score_type": "Primary",
  "scores": {
    "cvss_v40": null,
    "cvss_v31": 6.1,
    "cvss_v30": null
  },
  "references": [
    {
      "url": "https://support.apple.com/en-us/HT212256",
      "tags": [
        "Release Notes",
        "Vendor Advisory"
      ]
    },
    {
      "url": "https://support.apple.com/en-us/HT212257",
      "tags": [
        "Release Notes",
        "Vendor Advisory"
      ]
    },
    {
      "url": "https://support.apple.com/en-us/HT212258",
      "tags": [
        "Release Notes",
        "Vendor Advisory"
      ]
    },
    {
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-1879",
      "tags": [
        "US Government Resource"
      ]
    }
  ],
  "nvd_url": "https://nvd.nist.gov/vuln/detail/CVE-2021-1879",
  "covered_in": [],
  "attribution": [
    {
      "source": "NVD",
      "url": "https://nvd.nist.gov",
      "notice": "This product uses data from the NVD API but is not endorsed or certified by the NVD."
    },
    {
      "source": "CISA KEV",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "notice": "Known exploited vulnerabilities from the CISA KEV catalog."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss",
      "notice": "Exploit prediction scores from FIRST EPSS."
    }
  ]
}