CVE-2021-30858

Apple macOS, Apple iOS

Published 24 Aug 2021 · updated 17 Jun 2026 · Analyzed

8.8 High · CVSS 3.1, NVD

Exploited in the wild

CISA added this to its Known Exploited Vulnerabilities catalog on 3 Nov 2021, with a remediation deadline of 17 Nov 2021 for US federal agencies.

Required action: Apply updates per vendor instructions.

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.

References

seclists.org/fulldisclosure/2021/Sep/25 · Mailing List, Third Party Advisory
seclists.org/fulldisclosure/2021/Sep/27 · Mailing List, Third Party Advisory
seclists.org/fulldisclosure/2021/Sep/29 · Mailing List, Third Party Advisory
seclists.org/fulldisclosure/2021/Sep/38 · Mailing List, Third Party Advisory
seclists.org/fulldisclosure/2021/Sep/39 · Mailing List, Third Party Advisory
seclists.org/fulldisclosure/2021/Sep/50 · Mailing List, Third Party Advisory
www.openwall.com/lists/oss-security/2021/09/20/1 · Mailing List
www.openwall.com/lists/oss-security/2021/10/26/9 · Mailing List
www.openwall.com/lists/oss-security/2021/10/27/1 · Mailing List
www.openwall.com/lists/oss-security/2021/10/27/2 · Mailing List
www.openwall.com/lists/oss-security/2021/10/27/4 · Mailing List
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BO6DMTHZR57JDBOXPSNR2MKDMCRWV265/ · Release Notes
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XYNV7ASK4LQVAUMJXNXBS3Z7RVDQ2N3W/ · Release Notes
support.apple.com/en-us/HT212804 · Third Party Advisory
support.apple.com/en-us/HT212807 · Third Party Advisory
support.apple.com/kb/HT212824 · Third Party Advisory
www.debian.org/security/2021/dsa-4975 · Mailing List, Third Party Advisory
www.debian.org/security/2021/dsa-4976 · Mailing List, Third Party Advisory
www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-30858 · US Government Resource