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ABB Cylon Aspect 3.08.03 (MIX->UserManager) Auth Bypass Create MIXAdmin

Critical
Advisory ID
ZSL-2025-5939
Release Date
22 May 2025
Vendor
Affected Version
NEXUS Series, MATRIX-2 Series, ASPECT-Enterprise, ASPECT-Studio, Firmware: <=3.08.03
CVE
N/A
Tested On
GNU/Linux 3.15.10 (armv7l), GNU/Linux 3.10.0 (x86_64), GNU/Linux 2.6.32 (x86_64), Intel(R) Atom(TM) Processor E3930 @ 1.30GHz, Intel(R) Xeon(R) Silver 4208 CPU @ 2.10GHz, PHP/7.3.11, PHP/5.6.30, PHP/5.4.16, PHP/4.4.8, PHP/5.3.3, AspectFT Automation Application Server, lighttpd/1.4.32, lighttpd/1.4.18, Apache/2.2.15 (CentOS), OpenJDK Runtime Environment (rhel-2.6.22.1.-x86_64), OpenJDK 64-Bit Server VM (build 24.261-b02, mixed mode), ErgoTech MIX Deployment Server 2.0.0
Summary

ASPECT is an award-winning scalable building energy management and control solution designed to allow users seamless access to their building data through standard building protocols including smart devices.

Description

ABB Cylon Aspect BMS/BAS is vulnerable to a critical flaw in the AuthenticatedHttpServlet within its application server, enabling remote attackers to bypass authentication by setting the Host: 127.0.0.1 header. This deceives the server into processing requests as if they originate from localhost, granting unauthorized access to privileged operations. Specifically, this vulnerability impacts the UserManager and GroupManager servlets, allowing unauthenticated attackers to create and remove users and groups without credentials. The flaw stems from the servlet’s automatic authorization of localhost requests as the aamuser account, exposing these sensitive functions to both local and remote exploitation. By leveraging this bypass, attackers can manipulate user and group configurations, potentially escalating privileges or disrupting system access controls.

Proof of Concept
Disclosure Timeline
21.04.2024Vulnerability discovered.
22.04.2024Vendor contacted.
22.04.2024Vendor responds.
02.05.2024Working with the vendor.
21.05.2025No response from the vendor.
22.05.2025Public security advisory released.
Credits
Vulnerability discovered by Gjoko Krstic
References
Changelog
22.05.2025Initial release
26.05.2025Added reference [1]