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PatchSiren cyber security CVE debrief

CVE-2025-43300 Apple CVE debrief

CVE-2025-43300 is an Apple out-of-bounds write vulnerability affecting iOS, iPadOS, and macOS. CISA added it to the Known Exploited Vulnerabilities catalog on 2025-08-21, which makes this a high-priority remediation item for managed Apple fleets. The KEV entry sets a due date of 2025-09-11, so defenders should treat Apple’s official guidance as time-sensitive and validate remediation across endpoints and MDM-managed devices.

Vendor
Apple
Product
iOS, iPadOS, and macOS
CVSS
Unknown
CISA KEV
Listed
Original CVE published
2025-08-21
Original CVE updated
2025-08-21
Advisory published
2025-08-21
Advisory updated
2025-08-21

Who should care

Apple device administrators, endpoint security teams, IT operations, and incident response teams managing iPhone, iPad, or Mac fleets should prioritize this issue, especially in organizations that must track CISA KEV items on a fixed remediation timeline.

Technical summary

The supplied record identifies the issue as an out-of-bounds write in Apple iOS, iPadOS, and macOS. In general, out-of-bounds writes can corrupt memory and create reliability and security risk. The corpus does not include Apple’s advisory text or affected-version details, so the safest interpretation is limited to the vulnerability class, the affected product families, and the fact that CISA lists it as known exploited.

Defensive priority

High. Because CVE-2025-43300 is in CISA’s Known Exploited Vulnerabilities catalog, it should be treated as an urgent patch-or-mitigate item with attention to the 2025-09-11 due date.

Recommended defensive actions

  • Apply Apple’s official remediation guidance for the affected iOS, iPadOS, and macOS releases as soon as practical.
  • Verify exposure across all managed Apple devices, including BYOD devices that connect to corporate services if applicable.
  • Track the CISA KEV due date of 2025-09-11 in remediation workflows and exception management.
  • Use endpoint inventory and MDM reporting to confirm patch adoption and identify outliers.
  • If immediate remediation is not possible, follow vendor instructions and compensating controls based on your internal risk policy.

Evidence notes

This debrief is constrained to the supplied KEV record and official links only. The source metadata states: vendor Apple; product iOS, iPadOS, and macOS; vulnerability name 'Apple iOS, iPadOS, and macOS Out-of-Bounds Write Vulnerability'; dateAdded 2025-08-21; dueDate 2025-09-11; knownRansomwareCampaignUse Unknown. The CISA metadata also references Apple support pages 124925 through 124929 and the NVD detail page for CVE-2025-43300.

Sources and references

Verified primary and authoritative sources

  • CVE-2025-43300 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2025-43300

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2025-43300 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2025-43300

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

  • CISA Known Exploited Vulnerabilities catalog

    Publisher, destination, and source semantics verified

    URL: https://www.cisa.gov/known-exploited-vulnerabilities-catalog

    Cybersecurity and Infrastructure Security Agency - Official CISA catalog of vulnerabilities known to be exploited in the wild.

Supplemental references

  • Source item URL

    Unverified legacy reference

    URL: https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json

    cisa_kev

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.