CVE-2021-1789

Exp

A type confusion issue was addressed with improved state handling. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave, tvOS 14.4, watchOS 7.3, iOS 14.4 and iPadOS 14.4, Safari 14.0.3. Processing maliciously crafted web content may lead to arbitrary code execution.

Published: 2021-04-02 Last update: 2025-10-23 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-1789 is rated Active Exploitation (76.6/100): CVSS High severity, with low exploitation likelihood (EPSS 0.25%). CISA KEV confirms active exploitation (added 2022-05-04) affecting Apple / Multiple Products. a weakness (CWE-843) Unauthenticated remote administrative access may be possible. The CISA remediation deadline has passed—treat as an emergency patch priority.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

CISA KEV Record for CVE-2021-1789

Name: Apple Multiple Products Type Confusion Vulnerability · CISA KEV detail

Exploit added: 2022-05-04

Action due: 2022-05-25

Required action: Apply updates per vendor instructions.

Exploit prediction scoring system (EPSS) score for CVE-2021-1789

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-12-03 0.63% 0.25% -0.38%
2 2025-11-21 0.78% 0.63% -0.15%
3 2025-11-18 — 0.78% —

Full EPSS history (25 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-1789

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 5.9 [email protected]
8.8 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 5.9 134c704f-9b21-4f2e-91b3-4a467353bcc0
6.8 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.6 6.4 [email protected]

Weakness enumeration for CVE-2021-1789

OS Trackers for CVE-2021-1789

vendor priority summary link
alpine — CVE-2021-1789: 1 source package rows (webkit2gtk); 5 state rows across 5 repos (3.17-community, 3.18-community, 3.19-community, 3.20-community, edge-community); fixed 5, open 0. https://security.alpinelinux.org/vuln/CVE-2021-1789
debian not yet assigned CVE-2021-1789 not yet assigned priority: Debian including 2 source packages (webkit2gtk, wpewebkit), 10 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 10. https://security-tracker.debian.org/tracker/CVE-2021-1789
gentoo normal CVE-2021-1789: 1 GLSA(s) (202104-03), 1 atom(s) (net-libs/webkit-gtk); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2021-1789
redhat medium — https://access.redhat.com/security/cve/CVE-2021-1789
suse critical CVE-2021-1789 severity critical: SUSE including 215 source package names (LibRaw-0.19.5-3.el8, LibRaw-devel-0.19.5-3.el8, …), 454 product×package rows across 58 product lines (HPE Helion OpenStack 8, SUSE CaaS Platform 4.0, … (58 product lines)): Fixed 454. https://www.suse.com/security/cve/CVE-2021-1789/
ubuntu medium CVE-2021-1789 medium priority: Ubuntu including 5 source packages (qtwebkit-opensource-src, qtwebkit-source, webkit2gtk, webkitgtk, wpewebkit), 65 status rows across 13 suites (bionic, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, trusty, upstream, xenial): DNE 29, ignored 22, released 12, needs-triage 2. https://ubuntu.com/security/CVE-2021-1789

Affected software / configurations for CVE-2021-1789

Vendor Product Version Raw CPE
apple ipados < 14.4 cpe:2.3:o:apple:ipados:*:*:*:*:*:*:*:*
apple iphone_os < 14.4 cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*
apple mac_os_x >= 10.14, < 10.14.6 cpe:2.3:o:apple:mac_os_x:*:*:*:*:*:*:*:*
apple mac_os_x >= 10.15, < 10.15.7 cpe:2.3:o:apple:mac_os_x:*:*:*:*:*:*:*:*
apple mac_os_x 10.14.6 cpe:2.3:o:apple:mac_os_x:10.14.6:-:*:*:*:*:*:*
apple mac_os_x 10.14.6 cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2019-004:*:*:*:*:*:*
apple mac_os_x 10.14.6 cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2019-005:*:*:*:*:*:*
apple mac_os_x 10.14.6 cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2019-006:*:*:*:*:*:*
apple mac_os_x 10.14.6 cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2019-007:*:*:*:*:*:*
apple mac_os_x 10.14.6 cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2020-001:*:*:*:*:*:*
apple mac_os_x 10.14.6 cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2020-002:*:*:*:*:*:*
apple mac_os_x 10.14.6 cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2020-003:*:*:*:*:*:*
apple mac_os_x 10.14.6 cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2020-004:*:*:*:*:*:*
apple mac_os_x 10.14.6 cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2020-005:*:*:*:*:*:*
apple mac_os_x 10.14.6 cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2020-006:*:*:*:*:*:*
apple mac_os_x 10.14.6 cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2020-007:*:*:*:*:*:*
apple mac_os_x 10.14.6 cpe:2.3:o:apple:mac_os_x:10.14.6:supplemental_update:*:*:*:*:*:*
apple mac_os_x 10.14.6 cpe:2.3:o:apple:mac_os_x:10.14.6:supplemental_update_2:*:*:*:*:*:*
apple mac_os_x 10.15.7 cpe:2.3:o:apple:mac_os_x:10.15.7:-:*:*:*:*:*:*
apple mac_os_x 10.15.7 cpe:2.3:o:apple:mac_os_x:10.15.7:supplemental_update:*:*:*:*:*:*
apple macos >= 11.0, < 11.2 cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*
apple tvos < 14.4 cpe:2.3:o:apple:tvos:*:*:*:*:*:*:*:*
apple watchos < 7.3 cpe:2.3:o:apple:watchos:*:*:*:*:*:*:*:*
fedoraproject fedora 32 cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
fedoraproject fedora 33 cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
webkitgtk webkitgtk < 2.30.6 cpe:2.3:a:webkitgtk:webkitgtk:*:*:*:*:*:*:*:*

References for CVE-2021-1789

URL Tags
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JN6ZOD62CTO54CHTMJTHVEF6R2Y532TJ/ Broken Link Mailing List
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/L3L6ZZOU5JS7E3RFYGLP7UFLXCG7TNLU/ Broken Link Mailing List
https://security.gentoo.org/glsa/202104-03 Third Party Advisory
https://support.apple.com/en-us/HT212146 Release Notes Vendor Advisory
https://support.apple.com/en-us/HT212147 Release Notes Vendor Advisory
https://support.apple.com/en-us/HT212148 Release Notes Vendor Advisory
https://support.apple.com/en-us/HT212149 Release Notes Vendor Advisory
https://support.apple.com/en-us/HT212152 Release Notes Vendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-1789 US Government Resource
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