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PatchSiren cyber security CVE debrief

CVE-2020-9818 Apple CVE debrief

CVE-2020-9818 is an Apple out-of-bounds write issue affecting iOS, iPadOS, and watchOS. CISA has placed it in the Known Exploited Vulnerabilities catalog, so defenders should treat remediation as urgent and follow vendor update guidance.

Vendor
Apple
Product
iOS, iPadOS, and watchOS
CVSS
Unknown
CISA KEV
Listed
Original CVE published
2021-11-03
Original CVE updated
2021-11-03
Advisory published
2021-11-03
Advisory updated
2021-11-03

Who should care

Security and IT teams managing Apple iPhone, iPad, and Apple Watch fleets, especially organizations that rely on mobile device management, remote access, or bring-your-own-device programs.

Technical summary

The official records describe the flaw as an out-of-bounds write in Apple iOS, iPadOS, and watchOS. The supplied CISA KEV entry confirms the vulnerability is tracked as known exploited and directs administrators to apply updates per vendor instructions.

Defensive priority

High. CISA KEV inclusion means this issue should be prioritized over routine patch work and remediated as soon as possible across all affected Apple devices.

Recommended defensive actions

  • Apply the Apple updates that remediate CVE-2020-9818 per vendor instructions.
  • Verify coverage across all managed iOS, iPadOS, and watchOS devices, including any remote or lightly managed endpoints.
  • Confirm remediation status after patching and close any devices that remain on vulnerable versions.
  • Use CISA KEV and vendor advisories as the trigger for emergency patch prioritization on Apple mobile fleets.

Evidence notes

The supplied source corpus includes the CVE record, NVD detail page, and CISA KEV feed entry. CISA's KEV metadata names the issue as an Apple iOS, iPadOS, and watchOS out-of-bounds write vulnerability, sets a date added of 2021-11-03, and lists the required action as applying updates per vendor instructions. No CVSS score was provided in the supplied record.

Sources and references

Verified primary and authoritative sources

  • CVE-2020-9818 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2020-9818

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

  • CVE-2020-9818 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2020-9818

    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.