CVE-2024-8947 MicroPython objarray.c use after free
A use-after-free vulnerability in MicroPython's objarray component allows remote attackers to potentially execute code or cause denial of service via crafted bytes manipulation.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-8947?
CVE-2024-8947 is a medium-severity use after free vulnerability in MicroPython, published on 17 Sep 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A vulnerability was found in MicroPython 1.22.2. It has been declared as critical. Affected by this vulnerability is an unknown functionality of the file py/objarray.c. The manipulation leads to use after free. The attack can be launched remotely. The complexity of an attack is rather high. The exploitation appears to be difficult. Upgrading to version 1.23.0 is able to address this issue. The identifier of the patch is 4bed614e707c0644c06e117f848fa12605c711cd. It is recommended to upgrade the affected component. In micropython objarray component, when a bytes object is resized and copied into itself, it may reference memory that has already been freed.
Weakness: CWE-416
Which versions are affected by CVE-2024-8947?
6 open source packages ship an affected version, including micropython-copy and micropython-io. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
micropython-copy PyPI | All versions | None |
micropython-copy PyPI | All versions to 3.3.3.post3 | None |
micropython-copy PyPI | All versions to 3.3.3.post3 | None |
micropython-io PyPI | All versions | None |
micropython-io PyPI | All versions to 0.1 | None |
micropython-io PyPI | All versions to 0.1 | None |
Linux distribution packages (1)
micropython openSUSE:Tumbleweed | All versions | 1.28.0-2.1 |
Products include Micropython Micropython.
How do I fix CVE-2024-8947?
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-2024-8947 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2024-8947 exists.
Other vulnerabilities in MicroPython
- CVE-2023-7158 MicroPython objslice.c slice_indices heap-based overflow
- CVE-2024-8946 MicroPython VFS Unmount vfs.c mp_vfs_umount heap-based overflow
- CVE-2024-8948 MicroPython objint.c mpz_as_bytes heap-based overflow
- CVE-2023-7152 MicroPython modselect.c poll_set_add_fd use after free
- CVE-2026-1998 micropython runtime.c mp_import_all memory corruption
Sources
Also known as DEBIAN-CVE-2024-8947, GHSA-pwwp-3q7j-9mx8, PYSEC-2024-92, PYSEC-2024-94, UBUNTU-CVE-2024-8947, openSUSE-SU-2026:10704-1.