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CWE-290Weakness · CWE-290

CVE-2025-13953

CRITICAL · 9.3 CVSS v4.0 Published 2025-12-10
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
Bypass vulnerability in the authentication method in the GTT Tax Information System application, related to the Active Directory (LDAP) login method. Authentication is performed through a local WebSocket, but the web application does not properly validate the authenticity or origin of the data received, allowing an attacker with access to the local machine or internal network to impersonate the legitimate WebSocket and inject manipulated information. Exploiting this vulnerability could allow an attacker to authenticate as any user in the domain, without the need for valid credentials, compromising the confidentiality, integrity, and availability of the application and its data.

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 GTT Tax Information System uses a local WebSocket for authentication via Active Directory (LDAP). The application fails to validate the authenticity or origin of WebSocket data, allowing an attacker with local machine or internal network access to impersonate the legitimate WebSocket server and inject manipulated authentication data. This enables authentication as any domain user without valid credentials.

MitigationImplement proper WebSocket origin and data authenticity validation (e.g., cryptographic signatures, token-based authentication, mutual TLS), restrict WebSocket endpoints to authorized components, and add network segmentation to limit local/internal network attack surface.

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:H/VI:H/VA:H/SC:N/SI:N/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. Identify GTT Tax Information System installation
    Search for GTT Tax Information System in installed programs (Windows: Add/Remove Programs, Linux: package manager or /opt directory), or check for processes named 'gtt', 'tax', or related service names running on the host
    Affected if The application is installed and running on the target system
  2. Verify WebSocket service is active
    Check for listening WebSocket ports (common: 8080, 8443, or custom ports in application documentation), use netstat or ss to list open ports, or check application process for WebSocket module loading
    Affected if A WebSocket service is bound to a network port and accepting connections
  3. Confirm WebSocket-based LDAP authentication is configured
    Examine application configuration files (look for XML, JSON, YAML, or .config files in application directory) for LDAP/Active Directory integration settings that reference WebSocket, WS, or websocket authentication methods
    Affected if LDAP/Active Directory authentication is configured to use WebSocket transport
  4. Check WebSocket endpoint accessibility
    Review network binding configuration to determine if WebSocket listens on localhost only or on accessible network interfaces (0.0.0.0 or specific IP), check firewall rules or application host configuration
    Affected if WebSocket is accessible from internal network or localhost rather than restricted to loopback-only with strong authentication
  5. Inspect WebSocket data validation settings
    Review application configuration or source code for origin validation, cryptographic signatures, token-based authentication, or mutual TLS settings on the WebSocket endpoint
    Affected if WebSocket authentication lacks origin validation, cryptographic signing, tokens, or mTLS

The environment is affected if GTT Tax Information System is installed with WebSocket-based LDAP authentication enabled and the WebSocket endpoint lacks proper origin and data authenticity validation, making it exploitable by attackers with local or internal network access.

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 proper WebSocket origin and data authenticity validation (e.g., cryptographic signatures, token-based authentication, mutual TLS), restrict WebSocket endpoints to authorized components, and add network segmentation to limit local/internal network attack surface.

Have this fixed Scoped from the published advisory
  • Consultation6.0 h
  • Implementation12.0 h
  • Testing6.0 h
  • Review / QA4.0 h
28.0 hours of engineering $4,980
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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-2025-13953 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
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