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Fencer Vulns
high 8.8

CVE-2021-30952 kev in the critical feed json

An integer overflow was addressed with improved input validation.

published 2021-08-24 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-17869

cvss
8.8
version 3.1, CNA
cisa kev
Exploited
added 2026-03-05
epss
7.0%
EPSS 7.0% chance of exploitation in 30 days, percentile 94%
public exploits
0
none known

Summary

An integer overflow was addressed with improved input validation. This issue is fixed in tvOS 15.2, macOS Monterey 12.1, Safari 15.2, iOS 15.2 and iPadOS 15.2, watchOS 8.3. Processing maliciously crafted web content may lead to arbitrary code execution.

Patch / fix

cisa required action Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

  • Apple watchOS 8.3
  • Apple iOS and iPadOS 15.2
  • Apple macOS 12.1, 15.2
  • wpewebkit Debian 14, Debian 13, Debian 12 2.34.4-1
  • webkit2gtk Debian 14, Debian 13, Debian 12 2.34.4-1

debian advisories DEBIAN-CVE-2021-30952

  • webkit2gtk Ubuntu 20.04 LTS 2.34.4-0ubuntu0.20.04.1

ubuntu advisories UBUNTU-CVE-2021-30952

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

  • webkit2gtk3 RHEL 8 2.34.6-1.el8
  • webkit2gtk3-jsc RHEL 8 2.34.6-1.el8
  • webkitgtk4 RHEL 7 ELS 2.48.3-2.el7_9
  • webkitgtk4-jsc RHEL 7 ELS 2.48.3-2.el7_9

red hat advisories RHSA-2025:10364RHSA-2022:1777

  • webkit2gtk3 SLES for SAP 15 SP2, SLES 15 SP2-LTSS, SLES 15 SP2-BCL +9 more 2.34.6-29.1
  • webkit2gtk3 SLES for SAP 15 SP1, SLES for SAP 15, SLES 15-LTSS +7 more 2.34.6-3.97.1
  • webkit2gtk3 SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES for SAP 12 SP3 +11 more 2.34.5-2.85.3

suse advisories SUSE-SU-2022:0705-1SUSE-SU-2022:0703-1SUSE-SU-2022:0690-1

  • webkit2gtk3 openSUSE Leap 15.3 2.34.6-29.1

opensuse advisories openSUSE-SU-2022:0705-1

  • webkit2gtk3 AlmaLinux 8 2.34.6-1.el8
  • webkit2gtk3-jsc AlmaLinux 8 2.34.6-1.el8

almalinux advisories ALSA-2022:1777

  • webkit2gtk3 Rocky Linux 8 2.34.6-1.el8

rocky linux advisories RLSA-2022:1777

  • webkit2gtk Alpine 3.20, Alpine 3.19, Alpine 3.18 +2 more 2.34.4-r0

alpine advisories ALPINE-CVE-2021-30952

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

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-2021-30952 updated cvss 7.8

webkitgtk: Processing maliciously crafted web content may lead to arbitrary code execution

  • Red Hat Enterprise Linux 6 webkitgtk Red Hat Enterprise Linux 7 webkitgtk3, libwebkit2gtk
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux AppStream (v. 8) webkit2gtk3 2.34.6-1.el8, webkit2gtk3-jsc 2.34.6-1.el8
    fixed: vendor fix RHSA-2022:1777
  • Red Hat Enterprise Linux Server (v. 7 ELS) webkitgtk4 2.48.3-2.el7_9, webkitgtk4-jsc 2.48.3-2.el7_9 Red Hat Enterprise Linux Server Optional (v. 7 ELS) webkitgtk4-doc 2.48.3-2.el7_9, webkitgtk4-devel 2.48.3-2.el7_9, webkitgtk4-debuginfo 2.48.3-2.el7_9, webkitgtk4-jsc-devel 2.48.3-2.el7_9
    fixed: vendor fix RHSA-2025:10364
  • 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. CISA SSVC: exploitation active
  3. Added to CISA KEV
  4. CISA patch deadline

Known exploited

Added
8 mo ago
Patch by
2026-03-26 (7 mo ago)
Ransomware
Not known
Required action
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Vendor, product
Apple, Multiple Products
CISA name
Apple Multiple Products Integer Overflow or Wraparound Vulnerability

CISA SSVC

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

Exploit prediction

6.96% chance of exploitation in the next 30 days, higher than 94% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • cloud.google.com https://cloud.google.com/blog/topics/threat-intelligence/coruna-powerful-ios-exploit-kit referenced PoC, tagged "exploit" by a source, unverified

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 7.8 CVSS:3.1/AV:L/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 watchOS
  • Apple iOS and iPadOS
  • Apple macOS

Classification

Weakness
  • CWE-190 Integer Overflow or Wraparound

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.