Flask YeomanApplication · Flask Yeoman Project

CVE-2022-31559

CRITICAL · 9.3 CVSS v3.1 Published 2022-07-11
Fix available
A fix is available. Upgrade to after 2013-09-13 or later.
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
The tsileo/flask-yeoman repository through 2013-09-13 on GitHub allows absolute path traversal because the Flask send_file function is used unsafely.

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

The tsileo/flask-yeoman repository contains an absolute path traversal vulnerability caused by unsafe use of Flask's send_file function, allowing attackers to access arbitrary files on the server by supplying manipulated file paths.

MitigationImplement proper path validation using Flask's safe_join function or validate that resolved paths remain within an allowed directory before passing to send_file.

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
Flask YeomanApplication
Affected:<= 2013-09-13

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
Changed
Confidentiality
High
Integrity
None
Availability
Low

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

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. Check if flask-yeoman package is installed
    Run 'pip show flask-yeoman' or check requirements.txt for flask-yeoman entry
    Affected if flask-yeoman is present in the environment with a version dated 2013-09-13 or earlier (or no version specified, implying older release)
  2. Determine flask-yeoman installation date
    Run 'pip show flask-yeoman' and check the 'Release' or 'Published' field, or check git log for commit dates if cloned from repository
    Affected if Installation date or release date is on or before 2013-09-13
  3. Inspect source code for send_file usage
    Search the codebase for 'send_file' function calls, typically in route handlers that serve files
    Affected if Code contains send_file calls that accept path parameters without safe_join validation or directory containment checks
  4. Verify if user input reaches file path parameter
    Examine the send_file call and trace whether route parameters, query strings, or form inputs are passed directly to the send_file path argument
    Affected if User-controllable input (URL parameters, path variables, form data) flows directly into send_file without sanitization
  5. Check for safe_join or path validation implementation
    Search the codebase for 'safe_join' function usage or custom path validation logic that ensures the resolved path stays within an allowed directory
    Affected if No safe_join or equivalent path validation is present before send_file calls

You are affected if flask-yeoman is installed with a version from 2013-09-13 or earlier AND your application uses send_file to serve files with paths derived from user input without safe_join or directory-boundary validation.

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
Upgrade available Upgrade to a release after 2013-09-13
Interim mitigation

Implement proper path validation using Flask's safe_join function or validate that resolved paths remain within an allowed directory before passing to send_file.

Fix this in Flask Yeoman Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,490
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,984.

Scan for this in your stack

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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-2022-31559 in production — separate from our analysis above.

No notes yet

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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
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data