CVE-2021-1820 Information disclosure in iOS and iPadOS
Processing malicious web content may disclose process memory due to improper memory initialization in Apple operating systems.
- 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-2021-1820?
CVE-2021-1820 is a medium-severity 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 initialization issue was addressed with improved memory handling. 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 result in the disclosure of process memory.
Weakness: CWE-665
Which versions are affected by CVE-2021-1820?
It affects 5 products.
Products include Apple Ipados, Apple Iphone Os, Apple Macos, Apple Tvos, Apple Watchos.
How do I fix CVE-2021-1820?
Upgrade to a fixed version.
Is CVE-2021-1820 being exploited?
There is no known exploitation of CVE-2021-1820 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-2021-1820, GHSA-g25v-ch2q-jp7c, UBUNTU-CVE-2021-1820.