CVE-2021-1788 Use after free in iOS and iPadOS
Processing malicious web content allows arbitrary code execution via a use-after-free vulnerability in Apple operating systems and Safari.
- 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-2021-1788?
CVE-2021-1788 is a high-severity use after free vulnerability in Apple Ipados, published on 2 Apr 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 use after free issue was addressed with improved memory management. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave, tvOS 14.4, watchOS 7.3, iOS 14.4 and iPadOS 14.4, Safari 14.0.3. Processing maliciously crafted web content may lead to arbitrary code execution.
Weakness: CWE-416
Which versions are affected by CVE-2021-1788?
It affects 9 products.
Products include Apple Ipados, Apple Iphone Os, Apple Mac Os X, Apple Macos, Apple Safari, Apple Tvos and 3 more.
How do I fix CVE-2021-1788?
Upgrade to a fixed version.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2021-1788 being exploited?
There is no known exploitation of CVE-2021-1788 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-2021-1788, GHSA-7xrr-c599-c43j, UBUNTU-CVE-2021-1788.