SSA-367714

Siemens Security Advisory by Siemens ProductCERT

SSA-367714: Improper Integrity Check of Firmware Updates in SiPass integrated AC5102 / ACC-G2 and ACC-AP

Publication Date:	2025-05-23
Last Update:	2025-05-23
Current Version:	V1.0
CVSS v3.1 Base Score:	6.2
CVSS v4.0 Base Score:	8.2

SUMMARY

SiPass integrated ACC (Advanced Central Controller) devices do not properly check the integrity of firmware updates. This could allow an attacker to upload a maliciously modified firmware onto the device.

Siemens is preparing fix versions and recommends specific countermeasures for products where fixes are not, or not yet available.

KNOWN AFFECTED PRODUCTS

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Affected Product and Versions	Remediation
SiPass integrated AC5102 (ACC-G2) All versions affected by CVE-2022-31807	Currently no fix is available See recommendations from section Workarounds and Mitigations
SiPass integrated ACC-AP All versions affected by CVE-2022-31807	Currently no fix is available See recommendations from section Workarounds and Mitigations

WORKAROUNDS AND MITIGATIONS

Siemens has identified the following specific workarounds and mitigations that customers can apply to reduce the risk:

CVE-2022-31807: Enable TLS for communication between servers and affected devices; this mitigates the risk of on-path attackers that intercept and modify the firmware during transmission

Please follow the General Security Recommendations.

GENERAL SECURITY RECOMMENDATIONS

As a general security measure Siemens strongly recommends to protect network access to affected products with appropriate mechanisms. It is advised to follow recommended security practices in order to run the devices in a protected IT environment.

PRODUCT DESCRIPTION

AC5102 / ACC-G2 (Advanced Central Controller) is the central controller for SiPass integrated access control systems.

ACC-AP (Advanced Central Controller) is a door controller for up to two doors connected to an Internet/Intranet network for communication with the SiPass integrated access control system.

VULNERABILITY DESCRIPTION

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This chapter describes all vulnerabilities (CVE-IDs) addressed in this security advisory. Wherever applicable, it also documents the product-specific impact of the individual vulnerabilities.

Vulnerability CVE-2022-31807

Affected devices do not properly check the integrity of firmware updates. This could allow a local attacker to upload a maliciously modified firmware onto the device. In a second scenario, a remote attacker who is able to intercept the transfer of a valid firmware from the server to the device could modify the firmware "on the fly".

CVSS v3.1 Base Score	6.2
CVSS v3.1 Vector	CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
CVSS v4.0 Base Score	8.2
CVSS v4.0 Vector	CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
CWE	CWE-347: Improper Verification of Cryptographic Signature

ACKNOWLEDGMENTS

Siemens thanks the following party for its efforts:

Airbus Security for reporting the vulnerability

ADDITIONAL INFORMATION

For more information regarding the TLS-enabled communication between SiPass integrated and ACC devices, refer to the release notes of SiPass V2.95.03.18 and to chapter 3.1.1.8 in the document "ACC-AP - Controller and Device Installation Guide". On ACC devices, TLS-enabled communication is supported starting with firmware V6.5.1.

For further inquiries on security vulnerabilities in Siemens products and solutions, please contact the Siemens ProductCERT: https://www.siemens.com/cert/advisories

HISTORY DATA

V1.0 (2025-05-23):

Publication Date

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