How severe is CVE-2021-30823?

CVE-2021-30823 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2021-30823 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (79th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-30823?

CVE-2021-30823 primarily affects Apple Safari. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-30823?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-30823 published?

CVE-2021-30823 was published on 2021-10-28 and last updated on 2026-06-17.

CVE-2021-30823

CVE-2021-30823 is a medium-severity vulnerability in Apple Safari with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 4.0
EPSS exploit prediction: 2% (79th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Apple Safari
Published: 2021-10-28
Last modified: 2026-06-17

Description

A logic issue was addressed with improved restrictions. This issue is fixed in macOS Monterey 12.0.1, iOS 14.8 and iPadOS 14.8, tvOS 15, Safari 15, watchOS 8. An attacker in a privileged network position may be able to bypass HSTS.

Frequently asked questions

What is CVE-2021-30823?: A logic issue was addressed with improved restrictions. This issue is fixed in macOS Monterey 12.0.1, iOS 14.8 and iPadOS 14.8, tvOS 15, Safari 15, watchOS 8. An attacker in a privileged network position may be able to bypass HSTS.
How severe is CVE-2021-30823?: CVE-2021-30823 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2021-30823 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (79th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-30823?: CVE-2021-30823 primarily affects Apple Safari. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-30823?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-30823 published?: CVE-2021-30823 was published on 2021-10-28 and last updated on 2026-06-17.

References

Affected products (6)

cpe:2.3:a:apple:safari:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:ipados:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:tvos:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:watchos:*:*:*:*:*:*:*:*

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