CVE-2021-30661

Name: CVE-2021-30661
Creator: NVD / NIST
Published: 2021-09-08T15:15:13.32+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.8/10Actively ExploitedEPSS 4.26%

Last modified Jun 17, 2026

CVE-2021-30661 is a high-severity vulnerability rated 8.8/10 on the CVSS scale. A use after free issue was addressed with improved memory management. This issue is fixed in Safari 14.1, iOS 12.5.3, iOS 14.5 and iPadOS 14.5, watchOS 7.4, tvOS 14.5, macOS Big Sur 11.3. CISA has confirmed active exploitation in the wild. EPSS estimates a 4.26% chance of exploitation in the next 30 days.

Description

A use after free issue was addressed with improved memory management. This issue is fixed in Safari 14.1, iOS 12.5.3, iOS 14.5 and iPadOS 14.5, watchOS 7.4, tvOS 14.5, macOS Big Sur 11.3. Processing maliciously crafted web content may lead to arbitrary code execution. Apple is aware of a report that this issue may have been actively exploited..

Metrics

CVSS 3.1

8.8/10

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

EPSS Probability

4.26%

89.8th 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 Nov 17, 2021.

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Apple	Safari	< 14.1
Apple	Ipados	< 14.5
Apple	Iphone Os	< 12.5.3
Apple	Iphone Os	>= 14.0, < 14.5
Apple	Macos	>= 11.0, < 11.3
Apple	Tvos	< 14.5
Apple	Watchos	< 7.4

References

https://support.apple.com/en-us/HT212317Vendor Advisory
https://support.apple.com/en-us/HT212318Vendor Advisory
https://support.apple.com/en-us/HT212323Vendor Advisory
https://support.apple.com/en-us/HT212324Vendor Advisory
https://support.apple.com/en-us/HT212325Vendor Advisory
https://support.apple.com/en-us/HT212341Vendor Advisory
https://support.apple.com/en-us/HT212317Vendor Advisory
https://support.apple.com/en-us/HT212318Vendor Advisory
https://support.apple.com/en-us/HT212323Vendor Advisory
https://support.apple.com/en-us/HT212324Vendor Advisory
https://support.apple.com/en-us/HT212325Vendor Advisory
https://support.apple.com/en-us/HT212341Vendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-30661Third Party Advisory, US Government Resource

Timeline

Published: Sep 8, 2021
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2021-30661?

How severe is CVE-2021-30661?

CVE-2021-30661 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 4.26% probability of exploitation in the next 30 days. This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog.

How do I fix CVE-2021-30661?

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-2021-30661?

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

Scan your code now

Source: NVD / NIST