# CVE-2025-7705: ABB Busch-Welcome Door Opener Actuator authentication bypass

Source: https://junglewise.ai/threats/cve-2025-7705-abb-busch-welcome-door-opener-actuator-authentication-bypass  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-28. Updated: 2026-05-28  
License: CC BY 4.0 with a link back

CVE-2025-7705 · Severity: high · CVSS 6.8 · Published 2026-05-28

ABB Busch-Welcome door opener actuators, which are used to control physical access to buildings, contain a vulnerability that could allow unauthorized individuals to bypass security. By exploiting a misconfiguration in the device's operating mode, an attacker with physical access to the hardware could trigger the door to open. This poses a significant risk to the physical security of commercial facilities and residential buildings where these systems are installed.

Vendors: [ABB](https://junglewise.ai/threats/vendors/abb).

## Quick answers

**Is CVE-2025-7705 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2025-7705 being exploited in the wild.

**How severe is CVE-2025-7705?** High severity, with a CVSS score of 6.8, published 28 May 2026.

**Which products and versions are affected?** ABB Busch-Welcome 2 Wire Door Opener Actuator (Switch Actuator 4 DU - 83330) All versions; ABB Busch-Welcome 2 Wire Door Opener Actuator (Switch actuator, door/light 4 DU - 83330-500) All versions.

**Is there a fix for CVE-2025-7705?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2025-7705 attacked?** It is attacked with physical access, in a network appliance.

**Am I affected by CVE-2025-7705?** Check whether you run ABB Busch-Welcome 2 Wire Door Opener Actuator (Switch Actuator 4 DU - 83330), ABB Busch-Welcome 2 Wire Door Opener Actuator (Switch actuator or door/light 4 DU - 83330-500) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The ABB Busch-Welcome 2 Wire Door Opener Actuator (models 83330 and 83330-500) contains an authentication bypass vulnerability classified as CWE-489 (Active Debug Code). The issue stems from a compatibility mode being enabled by default, which can be exploited by an attacker with physical access to the device. Successful exploitation allows the attacker to bypass intended security controls and actuate the door opening mechanism. ABB has provided a manual remediation procedure involving toggling the physical mode switch between 'Door-Open' and 'Light' modes followed by a power reset to trigger a system recalibration and correct the misconfiguration.

## Affected products

- ABB Busch-Welcome 2 Wire Door Opener Actuator (Switch Actuator 4 DU - 83330) All versions
- ABB Busch-Welcome 2 Wire Door Opener Actuator (Switch actuator, door/light 4 DU - 83330-500) All versions

## Timeline

- 2025-07-21: advisory: Initial vendor advisory released by ABB
- 2026-05-28: advisory: CISA republication of the advisory

## References

- [https://www.cisa.gov/news-events/ics-advisories/icsa-26-148-04](https://www.cisa.gov/news-events/ics-advisories/icsa-26-148-04)