CVE-2021-1817 Memory corruption in iOS and iPadOS
Attackers can execute arbitrary code by tricking users into visiting malicious web content on Apple devices.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2021-1817?
CVE-2021-1817 is a high-severity memory corruption vulnerability in Apple Ipados, published on 8 Sep 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
A memory corruption issue was addressed with improved state management. This issue is fixed in macOS Big Sur 11.3, iOS 14.5 and iPadOS 14.5, watchOS 7.4, tvOS 14.5. Processing maliciously crafted web content may lead to arbitrary code execution.
Weakness: CWE-787
Which versions are affected by CVE-2021-1817?
It affects 5 products.
Products include Apple Ipados, Apple Iphone Os, Apple Macos, Apple Tvos, Apple Watchos.
How do I fix CVE-2021-1817?
Upgrade to a fixed version.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2021-1817 being exploited?
There is no known exploitation of CVE-2021-1817 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 DEBIAN-CVE-2021-1817, GHSA-wm9j-fw55-hv9g, UBUNTU-CVE-2021-1817.