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Fencer Vulns
high 8.8

CVE-2021-30858 kev in the critical feed json

A use after free issue was addressed with improved memory management.

published 2021-08-24 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-17775

cvss
8.8
version 3.1, CNA
cisa kev
Exploited
added 2021-11-03
epss
13.4%
EPSS 13.4% chance of exploitation in 30 days, percentile 96%
public exploits
0
none known

Summary

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.

Patch / fix

cisa required action Apply updates per vendor instructions.

  • Apple macOS 11.6
  • Apple iOS 14.8
  • wpewebkit Debian 14, Debian 13, Debian 12 2.32.4-1
  • webkit2gtk Debian 14, Debian 13, Debian 12 2.32.4-1

debian advisories DEBIAN-CVE-2021-30858

  • webkit2gtk Ubuntu 18.04 LTS 2.32.4-0ubuntu0.18.04.1
  • webkit2gtk Ubuntu 20.04 LTS 2.32.4-0ubuntu0.20.04.1

ubuntu advisories UBUNTU-CVE-2021-30858

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • webkitgtk4 RHEL 7 2.28.2-3.el7
  • webkitgtk4-jsc RHEL 7 2.28.2-3.el7
  • webkit2gtk3 RHEL 8 2.30.4-3.el8_4
  • webkit2gtk3-jsc RHEL 8 2.30.4-3.el8_4
  • webkit2gtk3 RHEL 8.2 EUS 2.24.4-4.el8_2
  • webkit2gtk3-jsc RHEL 8.2 EUS 2.24.4-4.el8_2
  • webkit2gtk3-plugin-process-gtk2 RHEL 8.2 EUS 2.24.4-4.el8_2
  • webkit2gtk3 RHEL 8.1 EUS 2.24.4-4.el8_1

red hat advisories RHSA-2022:0075RHSA-2022:0059RHSA-2021:4686RHSA-2021:4097

  • webkit2gtk3 SLES 15 SP2-BCL, SLE Real Time 15 SP2, SLE Module for Desktop Applications 15 SP3 +9 more 2.34.3-23.3
  • webkit2gtk3 SLES for SAP 15 SP1, SLES for SAP 15, SLES 15-LTSS +7 more 2.34.3-3.92.1
  • webkit2gtk3 SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES for SAP 12 SP3 +11 more 2.34.3-2.82.1
  • webkit2gtk3 SLE Module for Desktop Applications 15 SP3, SLE Module for Desktop Applications 15 SP2, SLE Module for Basesystem 15 SP3 +1 more 2.32.4-12.3
  • webkit2gtk3 SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES for SAP 12 SP3 +11 more 2.32.4-2.71.2
  • webkit2gtk3 SLES for SAP 15 SP1, SLES for SAP 15, SLES 15-LTSS +7 more 2.32.4-3.82.1

suse advisories SUSE-SU-2022:0182-2SUSE-SU-2022:0183-1SUSE-SU-2022:0182-1SUSE-SU-2022:0142-1SUSE-SU-2021:3353-1SUSE-SU-2021:3296-1

  • gtk3 openSUSE Tumbleweed 2.32.4-1.1
  • webkit2gtk3 openSUSE Leap 15.3 2.34.3-23.3
  • webkit2gtk3 openSUSE Leap 15.2 2.32.4-lp152.2.19.1
  • webkit2gtk3 openSUSE Leap 15.3 2.32.4-12.3

opensuse advisories openSUSE-SU-2024:11506-1openSUSE-SU-2022:0182-1openSUSE-SU-2021:1369-1openSUSE-SU-2021:3353-1

  • webkit2gtk3 Rocky Linux 8 2.30.4-3.el8_4

rocky linux advisories RLSA-2021:4097

  • webkit2gtk Alpine 3.20, Alpine 3.19, Alpine 3.18 +3 more 2.32.4-r0

alpine advisories ALPINE-CVE-2021-30858

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • wpewebkit Arch Linux 2.32.4-1

arch linux advisories AVG-2400

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-30858 updated cvss 8.8

webkitgtk: Use-after-free leading to arbitrary code execution

  • Red Hat Enterprise Linux 6 webkitgtk
    affected: workaround, no fix available “This flaw can be mitigated by either disabling JavaScript or by disabling IndexedDB”
  • Red Hat Enterprise Linux 7 webkitgtk3, libwebkit2gtk
    affected: workaround, no fix planned “This flaw can be mitigated by either disabling JavaScript or by disabling IndexedDB”
  • Red Hat Enterprise Linux AppStream (v. 8) webkit2gtk3 2.30.4-3.el8_4, webkit2gtk3-jsc 2.30.4-3.el8_4
    fixed: vendor fix “This flaw can be mitigated by either disabling JavaScript or by disabling IndexedDB” RHSA-2021:4097
  • Red Hat Enterprise Linux AppStream EUS (v. 8.1) webkit2gtk3 2.24.4-4.el8_1, webkit2gtk3-jsc 2.24.4-4.el8_1, webkit2gtk3-plugin-process-gtk2 2.24.4-4.el8_1
    fixed: vendor fix “This flaw can be mitigated by either disabling JavaScript or by disabling IndexedDB” RHSA-2021:4686
  • Red Hat Enterprise Linux AppStream EUS (v. 8.2) webkit2gtk3 2.24.4-4.el8_2, webkit2gtk3-jsc 2.24.4-4.el8_2, webkit2gtk3-plugin-process-gtk2 2.24.4-4.el8_2
    fixed: vendor fix “This flaw can be mitigated by either disabling JavaScript or by disabling IndexedDB” RHSA-2022:0075
  • Red Hat Enterprise Linux Client (v. 7) webkitgtk4 2.28.2-3.el7, webkitgtk4-jsc 2.28.2-3.el7 Red Hat Enterprise Linux Client Optional (v. 7) webkitgtk4-doc 2.28.2-3.el7, webkitgtk4-devel 2.28.2-3.el7, webkitgtk4-debuginfo 2.28.2-3.el7, webkitgtk4-jsc-devel 2.28.2-3.el7 Red Hat Enterprise Linux ComputeNode Optional (v. 7) webkitgtk4-doc 2.28.2-3.el7, webkitgtk4-devel 2.28.2-3.el7, webkitgtk4-debuginfo 2.28.2-3.el7, webkitgtk4-jsc-devel 2.28.2-3.el7 Red Hat Enterprise Linux Server (v. 7) webkitgtk4 2.28.2-3.el7, webkitgtk4-jsc 2.28.2-3.el7 Red Hat Enterprise Linux Server Optional (v. 7) webkitgtk4-doc 2.28.2-3.el7, webkitgtk4-devel 2.28.2-3.el7, webkitgtk4-debuginfo 2.28.2-3.el7, webkitgtk4-jsc-devel 2.28.2-3.el7 Red Hat Enterprise Linux Workstation (v. 7) webkitgtk4 2.28.2-3.el7, webkitgtk4-jsc 2.28.2-3.el7
    +1 more products
    Red Hat Enterprise Linux Workstation Optional (v. 7) webkitgtk4-doc 2.28.2-3.el7
    fixed: vendor fix “This flaw can be mitigated by either disabling JavaScript or by disabling IndexedDB” RHSA-2022:0059
  • Red Hat Enterprise Linux 9 webkit2gtk3, webkit2gtk3-jsc
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Timeline

  1. Published
  2. 0-day patched (Project Zero)
  3. Added to CISA KEV
  4. CISA patch deadline
  5. CISA SSVC: exploitation active

Known exploited

Added
5 y ago
Patch by
2021-11-17 (4 y ago)
Ransomware
Not known
Required action
Apply updates per vendor instructions.
Vendor, product
Apple, iOS, iPadOS, and macOS
CISA name
Apple iOS, iPadOS, macOS Use-After-Free Vulnerability

Zero-day

Detected in real attacks while still unknown to the vendor and the public, per Google Project Zero's 0day In-the-Wild tracker.

Patched
2021-09-13
Details
project zero root cause analysis

CISA SSVC

Exploitation
Active, exploited in the wild
Automatable
no
Technical impact
total
Assessed
21 mo ago

Exploit prediction

13.38% chance of exploitation in the next 30 days, higher than 96% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CNA 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD 2.0 6.8 AV:N/AC:M/Au:N/C:P/I:P/A:P

Affected products

  • Apple macOS
  • Apple iOS

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.