What’s Vulnerable › Vulnerabilities

CVE-2020-3856

• Severity: high (CVSS 7.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.9% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2020-02-27 · updated 2026-06-17
• Weakness: CWE-20

Description

A memory corruption issue was addressed with improved input validation. This issue is fixed in iOS 13.3.1 and iPadOS 13.3.1, macOS Catalina 10.15.3, tvOS 13.3.1, watchOS 6.1.2. Processing a maliciously crafted string may lead to heap corruption.

Affected products

• Apple iPadOS: before 13.3.1 — fixed in 13.3.1
• Apple Iphone Os: before 13.3.1 — fixed in 13.3.1
• macOS: before 10.15.3 — fixed in 10.15.3
• Apple tvOS: before 13.3.1 — fixed in 13.3.1
• Apple watchOS: before 6.1.2 — fixed in 6.1.2

How to fix

Upgrade to a fixed version: Apple iPadOS 13.3.1; Apple Iphone Os 13.3.1; macOS 10.15.3; Apple tvOS 13.3.1; Apple watchOS 6.1.2. Check the vendor advisory for mitigations.

References

• https://support.apple.com/HT210918
• https://support.apple.com/HT210919
• https://support.apple.com/HT210920
• https://support.apple.com/HT210921
• https://support.apple.com/HT210918
• https://support.apple.com/HT210919
• https://support.apple.com/HT210920
• https://support.apple.com/HT210921

Get alerted when CVE-2020-3856 or the next vulnerability affects your stack