HOMEVULNERABILITIESCVE-2021-1818
CRITICAL

CVE-2021-1818

NVD-CWE-noinfoPublished: April 2, 2021· Updated: Jun 17, 2026

9.8
CVSS v3.1

Official Description

A logic issue was addressed with improved state management. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave, watchOS 7.3, tvOS 14.4, iOS 14.4 and iPadOS 14.4. A remote attacker may be able to cause unexpected application termination or arbitrary code execution.

NVD Source

Technical Analysis

CVE-2021-1818 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Vendors & Products

Apple6 product(s)
ipad osiphone osmac os xmacostvoswatchos
Source: NVD CPE · 8 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttps://support.apple.com/en-us/HT212146
ADVISORYhttps://support.apple.com/en-us/HT212147
ADVISORYhttps://support.apple.com/en-us/HT212148
ADVISORYhttps://support.apple.com/en-us/HT212149
ADVISORYhttps://support.apple.com/en-us/HT212146
ADVISORYhttps://support.apple.com/en-us/HT212147
ADVISORYhttps://support.apple.com/en-us/HT212148
ADVISORYhttps://support.apple.com/en-us/HT212149

All References (8)

→
https://support.apple.com/en-us/HT212146Vendor Advisory
→
https://support.apple.com/en-us/HT212147Vendor Advisory
→
https://support.apple.com/en-us/HT212148Vendor Advisory
→
https://support.apple.com/en-us/HT212149Vendor Advisory
→
https://support.apple.com/en-us/HT212146Vendor Advisory
→
https://support.apple.com/en-us/HT212147Vendor Advisory
→
https://support.apple.com/en-us/HT212148Vendor Advisory
→
https://support.apple.com/en-us/HT212149Vendor Advisory

Quick Facts

CVE IDCVE-2021-1818
CVSS Score9.8 / 10
SeverityCRITICAL
WeaknessNVD-CWE-noinfo
CISA KEVNo
Affected1 vendor(s)
PublishedApr 2, 2021

Related CVEs (NVD-CWE-noinfo)

CVE-2013-2422
10.0
CVE-2009-2452
10.0
CVE-2012-1484
10.0
CVE-2023-45894
10.0
CVE-2005-2222
10.0
CVE-2009-1178
10.0

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2021-1818 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWatch. CVE data is provided under the NVD usage policy.
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