dbcve.org
Improper AuthenticationWeakness · CWE-287

CVE-2025-13427

MEDIUM · 6.9 CVSS v4.0 Published 2025-12-18
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
78/100
Remediation priority · High
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
An authentication bypass vulnerability in Google Cloud Dialogflow CX Messenger allowed unauthenticated users to interact with restricted chat agents, gaining access to the agents' knowledge and the ability to trigger their intents, by manipulating initialization parameters or crafting specific API requests. All versions after August 20th, 2025 have been updated to protect from this vulnerability. No user action is required for this.

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

This is an authentication bypass vulnerability in Google Cloud Dialogflow CX Messenger that allows unauthenticated users to access restricted chat agents by manipulating initialization parameters or crafting specific API requests. The flaw enables unauthorized access to agent knowledge bases and the ability to trigger intents without proper authentication credentials.

MitigationGoogle has already patched this vulnerability server-side in versions after August 20th, 2025; no user action is required. Organizations should verify their Dialogflow CX agents are using the updated version and review access logs for any suspicious unauthorized interactions.

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
Authentication
X
User interaction
None
Scope
X

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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 Dialogflow CX Messenger is in use
    Access Google Cloud Console and navigate to the Dialogflow CX section. Look for active agent configurations that include the Messenger integration (web chat widget, API calls to cx Messenger endpoints). Check project resources for dialogflow.googleapis.com services.
    Affected if The organization has deployed any Dialogflow CX agents with Messenger or web chat functionality enabled.
  2. Check agent or integration last updated timestamp
    In Google Cloud Console > Dialogflow CX > Select your agent > Go to Settings. Locate the creation date and last modified timestamp. Alternatively, check the Cloud Run service or Cloud Function that hosts the Messenger integration for deployment timestamp.
    Affected if The agent or Messenger integration was last updated or deployed before August 20th, 2025.
  3. Review Dialogflow CX API access logs for unauthenticated requests
    Go to Google Cloud Logging. Filter logs by resource type: "Dialogflow CX Agent" and look for requests with missing, empty, or invalid authentication tokens. Query for text like: resource.type="dialogflow.googleapis.com/Agent" AND authentication.principalEmail=NULL
    Affected if Logs contain API calls to agent endpoints that succeeded without valid authentication credentials or session tokens.
  4. Check for unauthorized intent triggering
    In Cloud Logging, query for Dialogflow CX intent match events. Look for intent.matches that occurred in rapid succession, from unusual IP addresses, or without corresponding client authentication. Query: resource.type="dialogflow.googleapis.com/Conversation" AND jsonPayload.matchIntent=true
    Affected if Intent matches or conversation events occurred without corresponding authenticated session identifiers.

An organization is affected if they use Dialogflow CX Messenger and discover any unauthenticated access attempts or unauthorized intent triggers in their logs, or if their agent integration predates the August 2025 server-side patch.

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

Google has already patched this vulnerability server-side in versions after August 20th, 2025; no user action is required. Organizations should verify their Dialogflow CX agents are using the updated version and review access logs for any suspicious unauthorized interactions.

Recommended fix High confidence
  1. No user action is required. Google has automatically deployed the fix to all Dialogflow CX Messenger instances as of August 20th, 2025.

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

Have this fixed Scoped from the published advisory
  • Consultation1.0 h
  • Testing2.0 h
  • Review / QA1.0 h
4.0 hours of engineering $750
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,200.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2025-13427 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2025-13427 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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