KnockpyApplication · Guelfoweb

CVE-2020-36941

CRITICAL · 9.8 CVSS v3.1 Published 2026-01-27
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
Public exploit 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
Knockpy 4.1.1 contains a CSV injection vulnerability that allows attackers to inject malicious formulas into CSV reports through unfiltered server headers. Attackers can manipulate server response headers to include spreadsheet formulas that will execute when the CSV is opened in spreadsheet applications.

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

Knockpy 4.1.1 is vulnerable to CSV injection (formula injection) because server response headers are written to CSV reports without sanitization. Attackers can manipulate HTTP response headers to contain spreadsheet formulas (e.g., formulas starting with =, +, -, @) that execute arbitrary commands when the victim opens the CSV in spreadsheet software like Excel or LibreOffice Calc.

MitigationImplement input validation and output encoding to sanitize all server header values before写入 CSV reports, stripping or escaping characters that could be interpreted as spreadsheet formulas (particularly characters like =, +, -, @, and tab).

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

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
KnockpyApplication
Affected:= 4.1.1

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. Identify Knockpy installation and version
    Run 'pip show knockpy' or check the installed package version using pip, or look for knockpy in your Python packages directory
    Affected if The installed version is Knockpy 4.1.1
  2. Locate CSV report output directory
    Search for CSV files generated by knockpy, typically in output folders or the current working directory where knockpy was run
    Affected if CSV reports exist and were generated by knockpy version 4.1.1
  3. Inspect CSV report headers for server header data
    Open any knockpy-generated CSV files and examine columns for server response header values (e.g., Server, X-Powered-By, custom headers)
    Affected if CSV files contain raw server header values without sanitization of formula characters (=, @, +, -, tab)
  4. Check for formula-like characters in header columns
    Use a text editor or 'grep' to search CSV content for lines starting with =, @, +, - or containing these characters at the start of header-related fields
    Affected if Server header fields in CSV start with =, @, +, - or contain these as leading characters which would execute when opened in spreadsheet software

You are affected if Knockpy version 4.1.1 is installed and has generated CSV reports containing unfiltered server header values that could contain spreadsheet formula injection characters.

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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Implement input validation and output encoding to sanitize all server header values before写入 CSV reports, stripping or escaping characters that could be interpreted as spreadsheet formulas (particularly characters like =, +, -, @, and tab).

Fix this in Knockpy Scoped from the published advisory
  • Consultation1.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,040
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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-2020-36941 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
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  • Version or environment caveats, and links to real fixes
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