---
id: CVE-2025-3449
title: >-
  A Generation of Predictable Numbers or Identifiers vulnerability in the SDM
  component of B&R Automation Runtime versions before 6.4 may allow an
  unauthenticated network-based attacker to take over already established
  sessions.
summary: >-
  A Generation of Predictable Numbers or Identifiers vulnerability in the SDM
  component of B&R Automation Runtime versions before 6.4 may allow an
  unauthenticated network-based attacker to take over already established
  sessions.
severity: medium
cvss: 4.2
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N'
cwe:
  - CWE-340
published: '2025-10-07'
updated: '2026-10-08'
sourceUpdated: '2026-10-08T22:10:00.563'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-3449'
references:
  - url: 'https://www.br-automation.com/fileadmin/SA25P003-178b6a20.pdf'
    label: cybersecurity@ch.abb.com
tags:
  - nvd
epss: 0.00192
epssPercentile: 0.08104
ingestedAt: '2026-10-08T22:11:53.800Z'
---

## Overview

A Generation of Predictable Numbers or Identifiers vulnerability in the SDM component of B&R Automation Runtime versions before 6.4 may allow an unauthenticated network-based attacker to take over already established sessions.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.