{
  "crds_version": "0.1",
  "kind": "base",
  "id": "crds:cve-2021-30952",
  "revision": 1,
  "title": "Apple Safari — integer overflow in web content to code execution",
  "summary": "An integer overflow in Apple's web content handling, fixed in tvOS 15.2, macOS Monterey 12.1, Safari 15.2, iOS and iPadOS 15.2 and watchOS 8.3, lets a crafted page run code on the device.",
  "source_type": "cve",
  "severity": "high",
  "cvss": {
    "score": 7.8,
    "vector": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
    "version": "3.1"
  },
  "epss": 0.06964,
  "exploitation": {
    "known_exploited": true,
    "exploit_available": true,
    "attack_complexity": "low",
    "kev_added": "2026-03-05",
    "prerequisites": "The user must open attacker-controlled web content in an affected browser."
  },
  "remediation": {
    "patch_available": true,
    "fixed_in": [
      "Safari 15.2",
      "iOS 15.2",
      "iPadOS 15.2",
      "macOS Monterey 12.1",
      "tvOS 15.2",
      "watchOS 8.3"
    ]
  },
  "mitre_attack": [
    "T1203"
  ],
  "kill_chain": "execution",
  "recommended_action": "Update to Safari 15.2, iOS and iPadOS 15.2, macOS Monterey 12.1, tvOS 15.2 or watchOS 8.3 now; it features in a commercial exploit kit.",
  "confidence": "high",
  "provenance": [
    {
      "fields": [
        "cvss",
        "exploitation.attack_complexity",
        "exploitation.exploit_available",
        "references",
        "published_at"
      ],
      "source": "https://nvd.nist.gov/vuln/detail/CVE-2021-30952",
      "retrieved_at": "2026-09-24T08:51:39.744Z",
      "confidence": "high",
      "extractor": "scrty-crds-pipeline/0.1"
    },
    {
      "fields": [
        "exploitation.known_exploited",
        "exploitation.kev_added"
      ],
      "source": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "retrieved_at": "2026-09-24T08:51:39.744Z",
      "confidence": "high",
      "extractor": "scrty-crds-pipeline/0.1"
    },
    {
      "fields": [
        "epss"
      ],
      "source": "https://api.first.org/data/v1/epss?cve=CVE-2021-30952",
      "retrieved_at": "2026-09-24T08:51:39.744Z",
      "confidence": "high",
      "extractor": "scrty-crds-pipeline/0.1"
    },
    {
      "fields": [
        "title",
        "summary",
        "severity",
        "remediation",
        "mitre_attack",
        "kill_chain",
        "recommended_action",
        "confidence",
        "tags",
        "exploitation.prerequisites"
      ],
      "source": "https://nvd.nist.gov/vuln/detail/CVE-2021-30952",
      "retrieved_at": "2026-09-24T08:51:39.744Z",
      "confidence": "high",
      "extractor": "claude-code"
    }
  ],
  "references": [
    {
      "type": "cve",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-30952",
      "label": "NVD record"
    },
    {
      "type": "cisa",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "label": "CISA Known Exploited Vulnerabilities catalog"
    },
    {
      "type": "vendor_advisory",
      "url": "https://support.apple.com/en-us/HT212975"
    },
    {
      "type": "vendor_advisory",
      "url": "https://support.apple.com/en-us/HT212976"
    },
    {
      "type": "vendor_advisory",
      "url": "https://support.apple.com/en-us/HT212978"
    }
  ],
  "published_at": "2021-08-24T19:15:21.777Z",
  "issued_at": "2026-09-24T08:51:39.744Z",
  "tags": [
    "apple",
    "safari",
    "webkit",
    "integer-overflow",
    "exploit-kit",
    "kev"
  ]
}