What’s Vulnerable › Vulnerabilities

CVE-2021-1844

• Severity: high (CVSS 8.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 2.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-04-02 · updated 2026-06-17
• Weakness: CWE-787

Description

A memory corruption issue was addressed with improved validation. This issue is fixed in iOS 14.4.1 and iPadOS 14.4.1, Safari 14.0.3 (v. 14610.4.3.1.7 and 15610.4.3.1.7), watchOS 7.3.2, macOS Big Sur 11.2.3. Processing maliciously crafted web content may lead to arbitrary code execution.

Affected products

• Apple iPadOS: before 14.4.1 — fixed in 14.4.1
• Apple Iphone Os: before 14.4.1 — fixed in 14.4.1
• Apple macOS: before 11.2.3 — fixed in 11.2.3
• Apple Safari: before 14.0.3 — fixed in 14.0.3
• Apple tvOS: before 14.5 — fixed in 14.5
• Apple watchOS: before 7.3.2 — fixed in 7.3.2
• Debian Linux: 10.0
• Fedoraproject Fedora: 33

How to fix

Upgrade to a fixed version: Apple iPadOS 14.4.1; Apple Iphone Os 14.4.1; Apple macOS 11.2.3; Apple Safari 14.0.3; Apple tvOS 14.5; Apple watchOS 7.3.2. Check the vendor advisory for mitigations.

References

• http://seclists.org/fulldisclosure/2021/Apr/55
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/L3L6ZZOU5JS7E3RFYGLP7UFLXCG7TNLU/
• https://support.apple.com/en-us/HT212220
• https://support.apple.com/en-us/HT212221
• https://support.apple.com/en-us/HT212222
• https://support.apple.com/en-us/HT212223
• https://support.apple.com/kb/HT212323
• https://www.debian.org/security/2021/dsa-4923
• http://seclists.org/fulldisclosure/2021/Apr/55
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/L3L6ZZOU5JS7E3RFYGLP7UFLXCG7TNLU/
• https://support.apple.com/en-us/HT212220
• https://support.apple.com/en-us/HT212221

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