Code InjectionWeakness · CWE-94

CVE-2024-3955

CRITICAL · 9.8 CVSS v3.1 Published 2024-05-02
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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).

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A command injection vulnerability exists in CraftBeerPi 4 where the 'logtime' GET parameter from the /downloadlog endpoint is passed directly to os.system() without any input validation or sanitization, allowing attackers to execute arbitrary system commands.

MitigationUpgrade to CraftBeerPi 4.4.1.a1 or later. Until patched, restrict network access to the CraftBeerPi web interface and implement Web Application Firewall rules to detect and block command injection patterns in URL parameters.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Confirm CraftBeerPi 4 is installed
    Identify the CraftBeerPi installation by checking for the web application process, the installation directory, or by accessing the web interface
    Affected if CraftBeerPi 4 is found running in the environment
  2. Check the installed CraftBeerPi version
    Locate and read the version file or check the package version (e.g., in setup.py, requirements.txt, or the application's version module)
    Affected if The version is earlier than 4.4.1.a1 (any 4.x.x version before 4.4.1.a1)
  3. Verify the /downloadlog endpoint exists
    Attempt to access the /downloadlog endpoint on the CraftBeerPi web server (e.g., http://<host>/downloadlog)
    Affected if The endpoint responds, indicating it is exposed
  4. Test if the logtime parameter is processed
    Send a benign GET request to /downloadlog?logtime=test and observe if the parameter is processed or returned in the response
    Affected if The parameter is accepted and processed by the application
  5. Confirm os.system() usage in the downloadlog handler
    Review the source code of the /downloadlog endpoint handler (typically in a routes or controller file) to verify that the logtime parameter is passed to os.system() without sanitization
    Affected if The code shows logtime parameter being passed directly to os.system()

The environment is affected if CraftBeerPi 4 version is earlier than 4.4.1.a1 AND the /downloadlog endpoint with the logtime parameter is accessible and passes the input unsanitized to os.system().

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade to CraftBeerPi 4.4.1.a1 or later. Until patched, restrict network access to the CraftBeerPi web interface and implement Web Application Firewall rules to detect and block command injection patterns in URL parameters.

Recommended fix High confidence

4.4.1.a1

  1. Backup the current CraftBeerPi installation and configuration
  2. Update CraftBeerPi to version 4.4.1.a1 (commit 57572c7) or later
  3. Restart the CraftBeerPi service to apply the changes
  4. Verify the upgrade was successful by checking the version

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,060
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2024-3955 in production — separate from our analysis above.

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What this is

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  • Version or environment caveats, and links to real fixes
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