Vulnerabilities
Misconfiguration
Compliance
CVE Vulnerabilities

CVE-2021-30661

Use After Free

Published: Sep 08, 2021 | Modified: Oct 23, 2025
CVSS 3.x
8.8
HIGH
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS 2.x
6.8 MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:P
RedHat/V2
RedHat/V3
8.8 MODERATE
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Ubuntu
MEDIUM
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Additional information
NVDhttps://nvd.nist.gov/vuln/detail/CVE-2021-30661
CWEhttps://cwe.mitre.org/data/definitions/416.html

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..

Weakness

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.

Affected Software

NameVendorStart VersionEnd Version
SafariApple*14.1 (excluding)
IpadosApple*14.5 (excluding)
Iphone_osApple*12.5.3 (excluding)
Iphone_osApple14.0 (including)14.5 (excluding)
MacosApple11.0 (including)11.3 (excluding)
TvosApple*14.5 (excluding)
WatchosApple*7.4 (excluding)
Red Hat Enterprise Linux 7 Extended Lifecycle SupportRedHatwebkitgtk4-0:2.48.3-2.el7_9*
Red Hat Enterprise Linux 8RedHatwebkit2gtk3-0:2.30.4-1.el8*
Qtwebkit-opensource-srcUbuntubionic*
Qtwebkit-opensource-srcUbuntudevel*
Qtwebkit-opensource-srcUbuntuesm-apps/bionic*
Qtwebkit-opensource-srcUbuntuesm-apps/focal*
Qtwebkit-opensource-srcUbuntuesm-apps/jammy*
Qtwebkit-opensource-srcUbuntuesm-apps/noble*
Qtwebkit-opensource-srcUbuntuesm-infra/xenial*
Qtwebkit-opensource-srcUbuntufocal*
Qtwebkit-opensource-srcUbuntuhirsute*
Qtwebkit-opensource-srcUbuntuimpish*
Qtwebkit-opensource-srcUbuntujammy*
Qtwebkit-opensource-srcUbuntukinetic*
Qtwebkit-opensource-srcUbuntulunar*
Qtwebkit-opensource-srcUbuntumantic*
Qtwebkit-opensource-srcUbuntunoble*
Qtwebkit-opensource-srcUbuntutrusty*
Qtwebkit-opensource-srcUbuntuupstream*
Qtwebkit-opensource-srcUbuntuxenial*
Qtwebkit-sourceUbuntubionic*
Qtwebkit-sourceUbuntuesm-apps/bionic*
Qtwebkit-sourceUbuntuesm-apps/xenial*
Qtwebkit-sourceUbuntutrusty*
Qtwebkit-sourceUbuntuxenial*
Webkit2gtkUbuntubionic*
Webkit2gtkUbuntudevel*
Webkit2gtkUbuntuesm-infra/bionic*
Webkit2gtkUbuntuesm-infra/focal*
Webkit2gtkUbuntuesm-infra/xenial*
Webkit2gtkUbuntufocal*
Webkit2gtkUbuntuhirsute*
Webkit2gtkUbuntuimpish*
Webkit2gtkUbuntujammy*
Webkit2gtkUbuntukinetic*
Webkit2gtkUbuntulunar*
Webkit2gtkUbuntumantic*
Webkit2gtkUbuntunoble*
Webkit2gtkUbuntuupstream*
Webkit2gtkUbuntuxenial*
WebkitgtkUbuntubionic*
WebkitgtkUbuntuesm-apps/bionic*
WebkitgtkUbuntuesm-apps/xenial*
WebkitgtkUbuntutrusty*
WebkitgtkUbuntuxenial*
WpewebkitUbuntuesm-apps/focal*
WpewebkitUbuntuesm-apps/jammy*
WpewebkitUbuntufocal*
WpewebkitUbuntuhirsute*
WpewebkitUbuntuimpish*
WpewebkitUbuntujammy*
WpewebkitUbuntutrusty*

Potential Mitigations

References

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