How severe is CVE-2021-1816?

CVE-2021-1816 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-1816 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (72nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-1816?

CVE-2021-1816 primarily affects Apple Ipados. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-1816?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-1816 published?

CVE-2021-1816 was published on 2021-09-08 and last updated on 2026-06-17.

CVE-2021-1816

CVE-2021-1816 is a high-severity vulnerability in Apple Ipados with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-119.

Key facts

Severity: High (CVSS 3.x base score 7.8)
CVSS v2: 9.3
EPSS exploit prediction: 2% (72nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-119
Affected product: Apple Ipados
Published: 2021-09-08
Last modified: 2026-06-17

Description

A buffer overflow was addressed with improved bounds checking. This issue is fixed in iOS 14.5 and iPadOS 14.5, watchOS 7.4, tvOS 14.5. A malicious application may be able to execute arbitrary code with kernel privileges.

Frequently asked questions

What is CVE-2021-1816?: A buffer overflow was addressed with improved bounds checking. This issue is fixed in iOS 14.5 and iPadOS 14.5, watchOS 7.4, tvOS 14.5. A malicious application may be able to execute arbitrary code with kernel privileges.
How severe is CVE-2021-1816?: CVE-2021-1816 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-1816 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (72nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-1816?: CVE-2021-1816 primarily affects Apple Ipados. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-1816?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-1816 published?: CVE-2021-1816 was published on 2021-09-08 and last updated on 2026-06-17.

References

Affected products (4)

cpe:2.3:o:apple:ipados:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:tvos:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:watchos:*:*:*:*:*:*:*:*

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