CVE-2021-30858

Exploitation

Exploited in the wild. Listed in the CISA Known Exploited Vulnerabilities catalog on 2021-11-03. Federal remediation due 2021-11-17.

SSVC decision

• ExploitationactiveCISA reports credible evidence of active exploitation.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

13.37% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 96.2% of scored records. A rank, not a probability.

NVD base score

8.8 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

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

NVD analysis status

Analyzed. NVD last modified this record on 2026-06-17.

Red Hat severity

Moderate. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2021-08-24 18:49Z5 YR AGO

Last updated

2025-10-21 23:25Z1 YR AGO

Reserved

2021-04-13

Assigning CNA

apple

Record state

PUBLISHED

Severity

High (CVSS 8.8)

CNA CVSS vector

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

Weaknesses

• CWE-416Use After FreeVariant

Data version

5.1

Document digest

0d38da2b58ba95159d05dc33f50583e4b58c142a05c1101875147b4bbc296813

• support.apple.comhttps://support.apple.com/en-us/HT212804x_refsource_MISC
• support.apple.comhttps://support.apple.com/en-us/HT212807x_refsource_MISC
• seclists.org20210917 APPLE-SA-2021-09-13-3 macOS Big Sur 11.6http://seclists.org/fulldisclosure/2021/Sep/27mailing-listx_refsource_FULLDISC
• seclists.org20210917 APPLE-SA-2021-09-13-1 iOS 14.8 and iPadOS 14.8http://seclists.org/fulldisclosure/2021/Sep/25mailing-listx_refsource_FULLDISC
• seclists.org20210917 APPLE-SA-2021-09-13-5 Safari 14.1.2http://seclists.org/fulldisclosure/2021/Sep/29mailing-listx_refsource_FULLDISC
• www.openwall.com[oss-security] 20210920 WebKitGTK and WPE WebKit Security Advisory WSA-2021-0005http://www.openwall.com/lists/oss-security/2021/09/20/1mailing-listx_refsource_MLIST
• lists.fedoraproject.orgFEDORA-2021-c00e45b6c0https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BO6DMTHZR57JDBOXPSNR2MKDMCRWV265/vendor-advisoryx_refsource_FEDORA
• seclists.org20210921 APPLE-SA-2021-09-20-6 Additional information for APPLE-SA-2021-09-13-1 iOS 14.8 and iPadOS 14.8http://seclists.org/fulldisclosure/2021/Sep/38mailing-listx_refsource_FULLDISC
• seclists.org20210921 APPLE-SA-2021-09-20-7 Additional information for APPLE-SA-2021-09-13-3 macOS Big Sur 11.6http://seclists.org/fulldisclosure/2021/Sep/39mailing-listx_refsource_FULLDISC
• www.debian.orgDSA-4975https://www.debian.org/security/2021/dsa-4975vendor-advisoryx_refsource_DEBIAN
• www.debian.orgDSA-4976https://www.debian.org/security/2021/dsa-4976vendor-advisoryx_refsource_DEBIAN
• support.apple.comhttps://support.apple.com/kb/HT212824x_refsource_CONFIRM
• seclists.org20210924 APPLE-SA-2021-09-23-1 iOS 12.5.5http://seclists.org/fulldisclosure/2021/Sep/50mailing-listx_refsource_FULLDISC
• lists.fedoraproject.orgFEDORA-2021-edf6957b7dhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XYNV7ASK4LQVAUMJXNXBS3Z7RVDQ2N3W/vendor-advisoryx_refsource_FEDORA
• www.openwall.com[oss-security] 20211026 WebKitGTK and WPE WebKit Security Advisory WSA-2021-0006http://www.openwall.com/lists/oss-security/2021/10/26/9mailing-listx_refsource_MLIST
• www.openwall.com[oss-security] 20211027 Re: WebKitGTK and WPE WebKit Security Advisory WSA-2021-0006http://www.openwall.com/lists/oss-security/2021/10/27/1mailing-listx_refsource_MLIST
• www.openwall.com[oss-security] 20211027 Re: WebKitGTK and WPE WebKit Security Advisory WSA-2021-0006http://www.openwall.com/lists/oss-security/2021/10/27/2mailing-listx_refsource_MLIST
• www.openwall.com[oss-security] 20211027 Re: WebKitGTK and WPE WebKit Security Advisory WSA-2021-0006http://www.openwall.com/lists/oss-security/2021/10/27/4mailing-listx_refsource_MLIST
• www.cisa.govhttps://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-30858government-resource