CVE-2021-30952

Name: CVE-2021-30952
Creator: NVD / NIST
Published: 2021-08-24T19:15:21.777+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.8/10Actively ExploitedEPSS 7.62%

Last modified Jun 17, 2026

CVE-2021-30952 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. 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. CISA has confirmed active exploitation in the wild. EPSS estimates a 7.62% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

7.8/10

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

EPSS Probability

7.62%

93.8th percentile

Probability of exploitation in the next 30 days. Learn more

Exploitation Status

This vulnerability is listed in CISA’s Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. Federal agencies must remediate by Mar 26, 2026.

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Apple	Safari	< 15.2
Apple	Ipados	< 15.2
Apple	Iphone Os	< 15.2
Apple	Macos	>= 12.0, < 12.1
Apple	Tvos	< 15.2
Apple	Watchos	< 8.3
Fedoraproject	Fedora	34
Fedoraproject	Fedora	35
Debian	Debian Linux	10.0
Debian	Debian Linux	11.0
Webkitgtk	Webkitgtk	< 2.34.4
Wpewebkit	Wpe Webkit	< 2.34.4

References

http://www.openwall.com/lists/oss-security/2022/01/21/2Mailing List, Third 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 Notes, Vendor Advisory
https://support.apple.com/en-us/HT212976Release Notes, Vendor Advisory
https://support.apple.com/en-us/HT212978Release Notes, Vendor Advisory
https://support.apple.com/en-us/HT212980Release Notes, Vendor Advisory
https://support.apple.com/en-us/HT212982Release Notes, Vendor Advisory
https://www.debian.org/security/2022/dsa-5060Mailing List, Third Party Advisory
https://www.debian.org/security/2022/dsa-5061Mailing List, Third Party Advisory
http://www.openwall.com/lists/oss-security/2022/01/21/2Mailing List, Third 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 Notes, Vendor Advisory
https://support.apple.com/en-us/HT212976Release Notes, Vendor Advisory
https://support.apple.com/en-us/HT212978Release Notes, Vendor Advisory
https://support.apple.com/en-us/HT212980Release Notes, Vendor Advisory
https://support.apple.com/en-us/HT212982Release Notes, Vendor Advisory
https://www.debian.org/security/2022/dsa-5060Mailing List, Third Party Advisory
https://www.debian.org/security/2022/dsa-5061Mailing List, Third Party Advisory
https://cloud.google.com/blog/topics/threat-intelligence/coruna-powerful-ios-exploit-kitExploit, Third Party Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-30952US Government Resource

Timeline

Published: Aug 24, 2021
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2021-30952?

How severe is CVE-2021-30952?

CVE-2021-30952 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 7.62% probability of exploitation in the next 30 days. This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog.

How do I fix CVE-2021-30952?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-30952?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST