# CVE-2025-13953: Bypass in the authentication method of the GTT Sistema de Información Tributario application

> An attacker can bypass authentication in the GTT Tax Information System by impersonating a local WebSocket, allowing unauthorized access to any user account.

- **Severity:** Critical 9.3 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 10 Dec 2025
- **Updated:** 10 Dec 2025
- **Also known as:** GHSA-5773-h955-5w49

## What is CVE-2025-13953?

CVE-2025-13953 is a critical authentication bypass vulnerability in GTT Sistema de Información Tributario, published on 10 Dec 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-290 (Authentication Bypass by Spoofing)

## Which versions are affected by CVE-2025-13953?


## How do I fix CVE-2025-13953?

No fix has been published for CVE-2025-13953 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-13953 being exploited?

There is no known exploitation of CVE-2025-13953 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-13953 and fix it if it is affected.

What it is: CVE-2025-13953 is a critical authentication bypass vulnerability in GTT Sistema de Información Tributario, published on 10 Dec 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-13953 in the wild and no public exploit code.

Affected product: GTT Sistema de Información Tributario. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-13953/ (Markdown: https://insights.sbomify.com/CVE-2025-13953/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-13953
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-13953
- OSV: https://osv.dev/vulnerability/CVE-2025-13953

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-13953/
Summaries are generated and may contain mistakes; the official description above is the record.