CVE-2021-30952

Apple Multiple Products Integer Overflow or Wraparound

7.8 HIGHActively exploited (CISA KEV)Public exploitEPSS 6.96%

Published24 Aug 2021
Added to CISA KEV5 Mar 2026
Remediation due26 Mar 2026

Description

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.

CVSS 3.1 breakdown

Attack vectorLocal

Attack complexityLow

Privileges requiredNone

User interactionRequired

ScopeUnchanged

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected products

Apple Safari< 15.2

Webkitgtk< 2.34.4

Wpewebkit Wpe Webkit< 2.34.4

Apple iPadOS< 15.2

Apple iPhone OS< 15.2

Apple macOS≥ 12.0 < 12.1

Apple Tvos< 15.2

Apple Watchos< 8.3

Debian Linux10.0 · 11.0

Fedoraproject Fedora34 · 35

Remediation

Fixed in

Apple Safari≥ 15.2

Webkitgtk≥ 2.34.4

Wpewebkit Wpe Webkit≥ 2.34.4

Apple iPadOS≥ 15.2

Apple iPhone OS≥ 15.2

Apple macOS≥ 12.1

Apple Tvos≥ 15.2

Apple Watchos≥ 8.3

Patch & vendor advisories

References

https://cloud.google.com/blog/topics/threat-intelligence/coruna-powerful-ios-exploit-kitExploitThird Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7EQVZ3CEMTINLBZ7PBC7WRXVEVCRHNSM/Broken Link
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HQKWD4BXRDD2YGR5AVU7H5J5PIQIEU6V/Broken Link
https://support.apple.com/en-us/HT212975Release NotesVendor Advisory
https://support.apple.com/en-us/HT212976Release NotesVendor Advisory
https://support.apple.com/en-us/HT212978Release NotesVendor Advisory
https://support.apple.com/en-us/HT212980Release NotesVendor Advisory
https://support.apple.com/en-us/HT212982Release NotesVendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-30952US Government Resource
https://www.debian.org/security/2022/dsa-5060Mailing ListThird Party Advisory

and 2 more references

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

Frequently asked

Is CVE-2021-30952 being actively exploited?

Yes. CVE-2021-30952 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added 5 Mar 2026.

How severe is CVE-2021-30952?

CVE-2021-30952 has a CVSS 3.1 base score of 7.8, rated high. EPSS estimates a 6.96% probability of exploitation.

Which products are affected by CVE-2021-30952?

Affected products include Apple Safari, Webkitgtk, Wpewebkit Wpe Webkit, Apple iPadOS, Apple iPhone OS, and 5 more.

How do I fix CVE-2021-30952?

Upgrade affected software to a fixed version, for example Apple Safari 15.2, Webkitgtk 2.34.4, Wpewebkit Wpe Webkit 2.34.4 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2021-30952 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. Because it is on the CISA KEV list, a risk for it never ranks below high, and the update that fixes it moves to the Emergency patch lane. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

See how prioritisation works Book a demo

Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.