Siemens SiPass
MonitorCVSS 6.2ICS-CERT ICSA-25-148-01May 23, 2025
Siemens
Attack path
Attack VectorLocal
Auth RequiredNone
ComplexityLow
User InteractionNone needed
Summary
SiPass integrated ACC (Advanced Central Controller) devices do not properly verify the integrity of firmware updates. This allows an attacker to upload maliciously modified firmware to the device without detection, potentially gaining full control over the access control system. Affected products are the ACC-G2 (AC5102) and ACC-AP models across all versions. No firmware updates are planned by Siemens to address this vulnerability.
What this means
What could happen
An attacker with local access to the device could upload maliciously modified firmware without detection, gaining complete control over the access controller and potentially preventing legitimate users from entering secured facilities or unlocking doors.
Who's at risk
Facility security teams and building operators using Siemens SiPass integrated access control systems, particularly those managing door locks, badge readers, and access permissions for security-sensitive areas such as data centers, manufacturing plants, and office buildings.
How it could be exploited
An attacker with local or network access to the SiPass ACC device could craft a modified firmware image and upload it via the management interface. Without firmware integrity verification, the device would accept and execute the malicious code, allowing the attacker to gain full control of the access control system.
Prerequisites
- Local or network access to the SiPass ACC device management interface
- Ability to initiate firmware upload process
No patch available (end-of-life products)Local access exploitation pathLow technical complexity to exploitCould compromise physical security of facilities
Exploitability
Unlikely to be exploited — EPSS score 0.1%
Affected products (2)
2 EOL
ProductAffected VersionsFix Status
SiPass integrated AC5102 (ACC-G2)All versionsNo fix (EOL)
SiPass integrated ACC-APAll versionsNo fix (EOL)
Remediation & Mitigation
0/4
Do now
0/2HARDENINGEnable TLS encryption for all communication between management servers and SiPass ACC devices to prevent on-path interception and modification of firmware during upload
HARDENINGRestrict network access to the SiPass ACC device management interface using firewall rules; allow updates only from authorized management workstations on dedicated administrative network segments
Schedule — requires maintenance window
0/1Patching may require device reboot — plan for process interruption
HARDENINGImplement strict change control procedures for any firmware updates; verify firmware sources and store only authorized updates in a secure, offline repository
Mitigations - no patch available
0/1The following products have reached End of Life with no planned fix: SiPass integrated AC5102 (ACC-G2), SiPass integrated ACC-AP. Apply the following compensating controls:
HARDENINGPhysically isolate SiPass ACC devices behind firewalls and implement network segmentation to prevent direct access from business networks or untrusted sources
CVEs (1)
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