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Vulnerability Intelligence

CVE-2021-1871

CriticalExploitedPublic exploit

webkitgtk: Logic issue leading to arbitrary code execution

Published Oct 13, 2021 · Updated Aug 4, 2026 · Also known as DEBIAN-CVE-2021-1871, UBUNTU-CVE-2021-1871

Key Facts

Patch immediately
  • CVE-2021-1871 is a critical-severity vulnerability (CVSS 9.8 v3.1) affecting Ipados (Apple), Iphone OS (Apple), macOS (Apple) and 22 more products.
  • It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Jan 26, 2021. Public exploit code is available.
  • EPSS estimates a 7.0% probability of exploitation in the next 30 days.
  • Fixed versions are available, including accountsservice 0.6.55-2.el8, accountsservice-devel 0.6.55-2.el8, accountsservice-libs 0.6.55-2.el8.
  • Brandefense priority: patch immediately, because it is listed as exploited in the wild.

CVSS v3.1

9.8

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

EPSS (30-day exploit likelihood)

7.0%

Higher than 94.0% of all scored CVEs

Exploited in the wild

Yes

4 catalog listings

Public exploit code

Available

Proof-of-concept or weaponized module

Get the full CVE-2021-1871 brief as a PDF

Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.

Description

A logic issue was addressed with improved restrictions. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave, iOS 14.4 and iPadOS 14.4. A remote attacker may be able to cause arbitrary code execution. Apple is aware of a report that this issue may have been actively exploited..

Known-Exploited Catalog Listings

CatalogAddedRemediation dueRansomware use
CISA KEVNov 3, 2021Nov 17, 2021Not reported
Industry KEV feedJan 26, 2021Nov 17, 2021Not reported
CIRCL KEVNov 3, 2021Nov 17, 2021Not reported
ENISA EUVDNov 3, 2021n/aNot reported

Required action: Apply updates per vendor instructions.

Affected Products

508 affected entries in total
ProductAffected versionsFixed in
IpadosAppleSee advisory14.4
Iphone OSAppleSee advisory14.4
macOSApple>= unspecified11.2
Mac OS XApple10.15.7, 10.15.7-security_update_2020, 10.15.7-supplemental_update10.15.7
Debian LinuxDebian10.0n/a
20 more affected products in the full CVE brief

Patched Releases

accountsservice

0.6.55-2.el8

accountsservice-devel

0.6.55-2.el8

accountsservice-libs

0.6.55-2.el8

Ipados

14.4

Iphone OS

14.4

Mac OS X

10.15.7

macOS

11.2

gdm

1:40.0-15.el8

gnome-autoar

0.2.3-2.el8

gnome-calculator

3.28.2-2.el8

gnome-classic-session

3.32.1-20.el8

gnome-control-center

3.28.2-28.el8

gnome-control-center-filesystem

3.28.2-28.el8

gnome-online-accounts

3.28.2-3.el8

gnome-online-accounts-devel

3.28.2-3.el8

gnome-session

3.28.1-13.0.1.el8, 3.28.1-13.el8

gnome-session-kiosk-session

3.28.1-13.0.1.el8

gnome-session-wayland-session

3.28.1-13.0.1.el8

gnome-session-xsession

3.28.1-13.0.1.el8

gnome-settings-daemon

3.32.0-16.el8, 3.32.0-16.el8_6.1, 3.32.0-16.el8.alma

gnome-shell

3.32.2-40.el8

gnome-shell-extension-apps-menu

3.32.1-20.el8

gnome-shell-extension-auto-move-windows

3.32.1-20.el8

gnome-shell-extension-common

3.32.1-20.el8

gnome-shell-extension-dash-to-dock

3.32.1-20.el8

Timeline

  1. Added to Industry KEV feed

    Jan 26, 2021

  2. Publicly disclosed

    Oct 13, 2021

  3. Added to CISA KEV

    Nov 3, 2021

  4. Added to CIRCL KEV

    Nov 3, 2021

  5. Added to ENISA EUVD

    Nov 3, 2021

  6. Last updated

    Aug 4, 2026

Weakness Type

  • CWE-20 Improper Input Validation

References

15 more references in the full CVE brief

FAQ

Common Questions.

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