CVE-2021-30661 Apple Multiple Products WebKit Storage Use-After-Free
Attackers can execute arbitrary code by tricking users into visiting malicious web content in Safari or WebKit-based apps.
- Exploited in the wild
- Since 3 Nov 2021
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2021-30661?
CVE-2021-30661 is a high-severity use after free 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 use after free issue was addressed with improved memory management. This issue is fixed in Safari 14.1, iOS 12.5.3, iOS 14.5 and iPadOS 14.5, watchOS 7.4, tvOS 14.5, macOS Big Sur 11.3. Processing maliciously crafted web content may lead to arbitrary code execution. Apple is aware of a report that this issue may have been actively exploited..
Weakness: CWE-416
Which versions are affected by CVE-2021-30661?
It affects 6 products.
Products include Apple Ipados, Apple Iphone Os, Apple Macos, Apple Safari, Apple Tvos, Apple Watchos.
How do I fix CVE-2021-30661?
Upgrade to a fixed version. US federal agencies must fix it by 17 Nov 2021.
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-2021-30661 being exploited?
Yes. Attackers have exploited CVE-2021-30661 in the wild since at least 3 Nov 2021.
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-2021-30661, GHSA-79qq-9x66-f5r5, UBUNTU-CVE-2021-30661.