CVE-2021-30823 Security feature bypass in Safari
An attacker in a privileged network position can bypass HSTS protections in Apple operating systems and Safari.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-30823?
CVE-2021-30823 is a medium-severity vulnerability in Apple Ipados, published on 28 Oct 2021. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
A logic issue was addressed with improved restrictions. This issue is fixed in macOS Monterey 12.0.1, iOS 14.8 and iPadOS 14.8, tvOS 15, Safari 15, watchOS 8. An attacker in a privileged network position may be able to bypass HSTS.
Which versions are affected by CVE-2021-30823?
It affects 6 products.
Products include Apple Ipados, Apple Iphone Os, Apple Macos, Apple Safari, Apple Tvos, Apple Watchos.
How do I fix CVE-2021-30823?
Upgrade to a fixed version.
Is CVE-2021-30823 being exploited?
There is no known exploitation of CVE-2021-30823 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-2021-30823, GHSA-fmvg-g54p-g6qj, UBUNTU-CVE-2021-30823.