CVE-2021-30858

Name: CVE-2021-30858
Creator: NVD / NIST
Published: 2021-08-24T19:15:14.253+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.8/10Actively ExploitedEPSS 13.49%

Last modified Jun 17, 2026

CVE-2021-30858 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 iOS 14.8 and iPadOS 14.8, macOS Big Sur 11.6. CISA has confirmed active exploitation in the wild. EPSS estimates a 13.49% 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 iOS 14.8 and iPadOS 14.8, macOS Big Sur 11.6. 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

13.49%

96.0th 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	Ipados	>= 13.1, < 14.8
Apple	Iphone Os	< 12.5.5
Apple	Iphone Os	>= 13.0, < 14.8
Apple	Macos	< 11.6
Fedoraproject	Fedora	33
Fedoraproject	Fedora	34
Debian	Debian Linux	10.0
Debian	Debian Linux	11.0

References

http://seclists.org/fulldisclosure/2021/Sep/25Mailing List, Third Party Advisory
http://seclists.org/fulldisclosure/2021/Sep/27Mailing List, Third Party Advisory
http://seclists.org/fulldisclosure/2021/Sep/29Mailing List, Third Party Advisory
http://seclists.org/fulldisclosure/2021/Sep/38Mailing List, Third Party Advisory
http://seclists.org/fulldisclosure/2021/Sep/39Mailing List, Third Party Advisory
http://seclists.org/fulldisclosure/2021/Sep/50Mailing List, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/09/20/1Mailing List
http://www.openwall.com/lists/oss-security/2021/10/26/9Mailing List
http://www.openwall.com/lists/oss-security/2021/10/27/1Mailing List
http://www.openwall.com/lists/oss-security/2021/10/27/2Mailing List
http://www.openwall.com/lists/oss-security/2021/10/27/4Mailing List
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BO6DMTHZR57JDBOXPSNR2MKDMCRWV265/Release Notes
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XYNV7ASK4LQVAUMJXNXBS3Z7RVDQ2N3W/Release Notes
https://support.apple.com/en-us/HT212804Third Party Advisory
https://support.apple.com/en-us/HT212807Third Party Advisory
https://support.apple.com/kb/HT212824Third Party Advisory
https://www.debian.org/security/2021/dsa-4975Mailing List, Third Party Advisory
https://www.debian.org/security/2021/dsa-4976Mailing List, Third Party Advisory
http://seclists.org/fulldisclosure/2021/Sep/25Mailing List, Third Party Advisory
http://seclists.org/fulldisclosure/2021/Sep/27Mailing List, Third Party Advisory
http://seclists.org/fulldisclosure/2021/Sep/29Mailing List, Third Party Advisory
http://seclists.org/fulldisclosure/2021/Sep/38Mailing List, Third Party Advisory
http://seclists.org/fulldisclosure/2021/Sep/39Mailing List, Third Party Advisory
http://seclists.org/fulldisclosure/2021/Sep/50Mailing List, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/09/20/1Mailing List
http://www.openwall.com/lists/oss-security/2021/10/26/9Mailing List
http://www.openwall.com/lists/oss-security/2021/10/27/1Mailing List
http://www.openwall.com/lists/oss-security/2021/10/27/2Mailing List
http://www.openwall.com/lists/oss-security/2021/10/27/4Mailing List
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BO6DMTHZR57JDBOXPSNR2MKDMCRWV265/Release Notes
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XYNV7ASK4LQVAUMJXNXBS3Z7RVDQ2N3W/Release Notes
https://support.apple.com/en-us/HT212804Third Party Advisory
https://support.apple.com/en-us/HT212807Third Party Advisory
https://support.apple.com/kb/HT212824Third Party Advisory
https://www.debian.org/security/2021/dsa-4975Mailing List, Third Party Advisory
https://www.debian.org/security/2021/dsa-4976Mailing List, Third Party Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-30858US Government Resource

Timeline

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

Frequently Asked Questions

What is CVE-2021-30858?

How severe is CVE-2021-30858?

CVE-2021-30858 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 13.49% probability of exploitation in the next 30 days. This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog.

How do I fix CVE-2021-30858?

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-2021-30858?

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

Scan your code now

Source: NVD / NIST