CVE-2020-3856 Memory corruption in iOS
Attackers can execute arbitrary code by tricking users into processing a maliciously crafted string, affecting Apple operating systems.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2020-3856?
CVE-2020-3856 is a high-severity memory corruption vulnerability in Apple Ipados, published on 27 Feb 2020. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official 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.
Which versions are affected by CVE-2020-3856?
It affects 5 products.
Products include Apple Ipados, Apple Iphone Os, Apple Mac Os X, Apple Tvos, Apple Watchos.
How do I fix CVE-2020-3856?
No fix has been published for CVE-2020-3856 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2020-3856 being exploited?
There is no known exploitation of CVE-2020-3856 in the wild and no public exploit code.
Other vulnerabilities in Apple Ipados
- CVE-2025-43300 Apple iOS, iPadOS, and macOS Out-of-Bounds Write
- CVE-2025-24201 Apple Multiple Products WebKit Out-of-Bounds Write
- CVE-2025-24085 Apple Multiple Products Use-After-Free
- CVE-2025-31200 Apple Multiple Products Memory Corruption
- CVE-2025-31201 Apple Multiple Products Arbitrary Read and Write
Sources
Also known as GHSA-rrw9-w2gg-fc6m.