Skip to content
Fencer Vulns
medium 5.5

CVE-2021-30836 json

An out-of-bounds read was addressed with improved input validation.

published 2021-10-28 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-17753

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.1%
EPSS 1.1% chance of exploitation in 30 days, percentile 65%
public exploits
0
none known

Summary

An out-of-bounds read was addressed with improved input validation. This issue is fixed in iOS 14.8 and iPadOS 14.8, tvOS 15, watchOS 8, iOS 15 and iPadOS 15. Processing a maliciously crafted audio file may disclose restricted memory.

Patch / fix

  • Apple iOS and iPadOS 14.8, 15
  • Apple tvOS 15
  • Apple watchOS 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-2021-30836

  • 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-2021-30836

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 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

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

  • webkit2gtk3 openSUSE Leap 15.3 2.34.3-23.3

opensuse advisories openSUSE-SU-2022:0182-1

  • 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 2.32.4-r0

alpine advisories ALPINE-CVE-2021-30836

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-2021-30836 updated cvss 5.5

webkitgtk: Out-of-bounds read leading to memory disclosure

  • 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

Exploit prediction

1.10% chance of exploitation in the next 30 days, higher than 65% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:P/I:N/A:N

Affected products

  • Apple iOS and iPadOS
  • Apple tvOS
  • Apple watchOS

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.