# ABB EIBPORT session management flaw allows unauthenticated access

Published: 2026-05-28 · Severity: routine · Sectors: manufacturing, infrastructure
Canonical: https://vorant.io/reports/b533bb9f-6b7b-5b17-9179-a11c085ed5af/abb-eibport-session-management-flaw-allows-unauthenticated-access

> ABB EIBPORT building automation controllers below firmware 3.9.2 have broken session management; an unauthenticated attacker can access the device without authentication.

ABB has released a security advisory for EIBPORT, a building management system used to automate buildings according to KNX standards. The advisory covers three product variants: EIBPORT V3 KNX (models 2CLA963710W1001 and 2CSM256242R2001) and EIBPORT V3 KNX GSM (model 2CLA963720W1001). All versions below 3.9.2 are affected by a session management vulnerability (CVE-2021-22291) that stems from improper credential and session token verification.

The core issue is that the device's session management fails to securely maintain authentication state, allowing an unauthenticated attacker to gain access to the device without proper credentials. Once an attacker has access, they can read sensitive information stored on the device and modify its configuration. However, ABB explicitly states that the vulnerability cannot be exploited remotely under properly configured networks—EIBPORT devices should be physically protected, isolated from the Internet, and separated from untrusted networks by a firewall with minimal exposed ports. ABB notes that some customers have deployed EIBPORT against intended use by exposing the device's IP address over the Internet or untrusted networks, creating remote exploitation risk.

No public exploitation has been reported as of the advisory date. The vulnerability was privately reported. ABB has released a firmware update (version 3.9.2 or later) that remediates the issue by correcting login credential verification and session identifier handling, and hardens product configuration. Affected organizations should apply the update at their earliest convenience, and ensure EIBPORT devices remain isolated from untrusted networks and the Internet.

## Mentioned in this report

- Vulnerabilities: CVE-2021-22291

Source reporting: https://www.cisa.gov/news-events/ics-advisories/icsa-26-148-03

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