IRONSMITHINTEL
HIGHCVSS7.8
|
Actively Exploited
|CISA KEV|CVE-2021-30952|Auth: none — unauthenticated|Reboot: required|Manual only

Apple Multiple Products Integer Overflow or Wraparound Vulnerability

Apple tvOS, macOS, Safari, iPadOS and watchOS contain an integer overflow or wraparound vulnerability due to the processing of maliciously crafted web content that may lead to arbitrary code execution.

Published Aug 24, 2021 · Updated May 16, 2026
Why patchRisk explained in plain English
Worst-case scenarioIf unpatched

A local attacker, without authentication, can achieve full data confidentiality loss, arbitrary modification of data, complete denial of service or system unavailability. Federal agencies are required to remediate by 2026-03-26 under CISA BOD 22-01.

How the attack worksNo clicks needed

This is a Integer Overflow (CWE-190) vulnerability in Apple Multiple Products. An integer overflow was addressed with improved input validation. This issue is fixed in tvOS 15.2, macOS Monterey 12.1, Safari 15.2, iOS 15.2 and iPadOS 15.2, watchOS 8.3. Processing maliciously crafted web content may lead to arbitrary code execution. Exploitation requires local access, low attack complexity, no authentication required, and user interaction required.

Am I affected?Quick check

Probably yes if any of these apply:

Apple Device Administrators
Endpoint Security
IT Security
Running safari: v < 15.2; ipados: v < 15.2; iphone os: v < 15.2; macos: 12.0 ≤ v < 12.1; tvos: v < 15.2; watchos: v < 8.3; fedora: 34, 35; debian linux: 10.0, 11.0; webkitgtk: v < 2.34.4; wpe webkit: v < 2.34.4
Real-world incidentsWhat we've seen

Active exploitation documented in the wild. Threat-research write-up: https://cloud.google.com/blog/topics/threat-intelligence/coruna-powerful-ios-exploit-kit

How to patch

Manual remediation steps

Apply the Vendor Patch

This vulnerability is in the CISA Known Exploited Vulnerabilities catalog — apply the vendor's security update as soon as possible.

CISA required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

References

    1
    Vendor advisory: https://support.apple.com/en-us/HT212975
    1
    NVD entry: https://nvd.nist.gov/vuln/detail/CVE-2021-30952
    1
    CISA KEV: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-30952
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