CVE-2021-36976 Use after free in n/a
A use-after-free vulnerability in libarchive allows attackers to execute arbitrary code or cause a denial of service via crafted archives.
- 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-2021-36976?
CVE-2021-36976 is a medium-severity use after free vulnerability in Apple Ipados, published on 20 Jul 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
libarchive 3.4.1 through 3.5.1 has a use-after-free in copy_string (called from do_uncompress_block and process_block).
Weakness: CWE-416
Which versions are affected by CVE-2021-36976?
It affects 7 products.
Products include Apple Ipados, Apple Iphone Os, Apple Macos, Apple Watchos, Fedoraproject Fedora, Libarchive Libarchive and 1 more.
How do I fix CVE-2021-36976?
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-2021-36976 being exploited?
There is no known exploitation of CVE-2021-36976 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 ALPINE-CVE-2021-36976, AZL-6614, DEBIAN-CVE-2021-36976, GHSA-4fxq-mcvv-8fqm, JLSEC-2025-234, OESA-2021-1398 and 1 more.