TornadoApplication · Tornadoweb

CVE-2023-28370

MEDIUM · 6.1 CVSS v3.1 Published 2023-05-25
Fix available
A fix is available. Upgrade to 6.3.2 or later.
See remediation →
68/100
Remediation priority · Elevated
Remotely reachable No privileges

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
Open redirect vulnerability in Tornado versions 6.3.1 and earlier allows a remote unauthenticated attacker to redirect a user to an arbitrary web site and conduct a phishing attack by having user access a specially crafted URL.

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

Tornado web framework versions 6.3.1 and earlier contain an open redirect vulnerability where the application fails to properly validate redirect URLs. An attacker can craft a malicious URL containing an arbitrary external domain that the vulnerable application will redirect users to, enabling phishing attacks.

MitigationUpgrade Tornado to the patched version (6.3.2 or later). Additionally, implement strict allowlist-based validation for any redirect parameters to prevent external URL redirection.

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
TornadoApplication
Affected:< 6.3.2

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
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

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

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 installed Tornado version
    Run 'python -c "import tornado; print(tornado.version)"' or check your requirements.txt/package-lock.json for the tornado version entry
    Affected if The version is 6.3.1 or earlier (any version below 6.3.2)
  2. Locate redirect usage in application code
    Search your codebase for calls to 'self.redirect' or 'RequestHandler.redirect' methods
    Affected if Your application uses the redirect() method to handle redirects
  3. Determine if redirect target accepts user input
    Review the redirect logic: check if the URL/target passed to redirect() comes from request parameters (e.g., request.args, request.query), path variables, or user-controlled data
    Affected if Redirect targets are derived from user-supplied input without strict allowlist validation
  4. Review redirect validation implementation
    Examine any validation logic applied to redirect URLs (e.g., checks for allowed domains, path validation)
    Affected if No validation exists or validation only checks for relative paths without restricting to an allowlist of permitted domains

You are affected if your Tornado version is below 6.3.2 AND your application uses redirect() with URLs derived from user input without strict allowlist-based domain 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.

dbcve · scoped
Upgrade available Upgrade to 6.3.2 or later
Fixed in 6.3.2
Interim mitigation

Upgrade Tornado to the patched version (6.3.2 or later). Additionally, implement strict allowlist-based validation for any redirect parameters to prevent external URL redirection.

Recommended fix High confidence

Tornado 6.3.2

  1. Check the current installed version of Tornado using: pip show tornado
  2. Upgrade Tornado to version 6.3.2 or later using: pip install --upgrade tornado>=6.3.2
  3. Verify the upgrade was successful by running: pip show tornado and confirming the version number
  4. Test that the application functions correctly after the upgrade
Caveat Review the Tornado 6.3.2 release notes for any changes; patch releases typically have minimal breaking changes

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

Fix this in Tornado Scoped from the published advisory
  • Consultation4.0 h
  • Implementation2.0 h
  • Testing6.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,420
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,872.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2023-28370 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

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-2023-28370 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