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CVE-2025-13953VulnerabilityPublished

CVE-2025-13953: GTT Sistema de Información Tributario · Authentication Bypass by Spoofing

Affects GTT Sistema de Información TributarioSource CVE Database V5

0

Not known to be exploited · CVSS 9.3 Critical.

Data as of 26 Oct 2026, 06:26 UTC

CVSS 4.0 base score
9.3Critical
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.5% chance of exploitation in 30 days – higher than 46% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
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

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 10 Dec 2025

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.

What to do

Affected software

ProductAffectedFixed in
GTT Sistema de Información TributarioAffected
  • *
Fixed in–

AI-suggested

To mitigate this vulnerability, European organizations should implement multiple layers of defense: 1) Apply strict validation of WebSocket connections by enforcing origin checks and verifying authentication tokens or implementing mutual TLS to ensure only legitimate clients can establish connections. 2) Restrict internal network access to the tax information system using network segmentation and firewall rules to limit exposure to trusted devices and users. 3) Monitor authentication logs and WebSocket traffic for anomalies indicative of spoofing or injection attempts, employing intrusion detection systems tailored to WebSocket protocols. 4) Enforce strong endpoint security to prevent local machine compromise, including up-to-date antivirus, endpoint detection and response (EDR), and regular patching. 5) Engage with the vendor (GTT) for patches or updates addressing this vulnerability as they become available, and plan for rapid deployment. 6) Conduct regular security audits and penetration testing focused on internal network and WebSocket communication security. 7) Educate internal users about the risks of internal network threats and enforce strict access controls and least privilege principles. These measures, combined, reduce the likelihood of successful exploitation and limit potential damage.

Description

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.

References

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