CVE-2024-8947 — micropython-copy
Fix: micropython/micropython@4bed614CVE-2024-8947 is a Use After Free vulnerability in micropython-copy. 2 public exploit references exist, so weaponization risk is real. No vendor fix is recorded yet; mitigation options are listed below.
MicroPython objarray.c use after free
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for CVE-2024-8947.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
micropython-copy🐍micropython-ioReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | micropython-copy | all versions | No fix |
| 🐍PyPI | micropython-io | all versions | No fix |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for micropython-copy, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
No patched version of micropython-copy has shipped for CVE-2024-8947 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2024-8947 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2024-8947. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2024-8947 in your dependencies?
O3 Security finds CVE-2024-8947 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.