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PatchSiren cyber security CVE debrief

CVE-2025-31930 Siemens CVE debrief

CVE-2025-31930 affects multiple Siemens VersiCharge AC and related EV charger products because Modbus service is enabled by default. According to the CISA CSAF advisory and Siemens references, an attacker already connected to the same network could use that service to remotely control the charger. The published CVSS 3.1 vector (AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H) reflects the potential for high-impact control over device behavior. Siemens lists a vendor fix in version V2.135 or later, with OTA delivery available for fully commissioned devices connected to Siemens Device Management.

Vendor
Siemens
Product
IEC 1Ph 7.4kW Child socket (8EM1310-2EH04-0GA0)
CVSS
HIGH 8.8
CISA KEV
Not listed in stored evidence
Original CVE published
2025-05-13
Original CVE updated
2025-05-13
Advisory published
2025-05-13
Advisory updated
2025-05-13

Who should care

Siemens EV charger operators, facility and fleet charging administrators, OT/ICS security teams, and any organization running the affected Siemens charger models on an internal or shared network should treat this as a priority issue.

Technical summary

The advisory describes a default-enabled Modbus service on affected chargers. Because Modbus is reachable from the local network, a nearby attacker with access to the same network may issue commands that alter charger operation. The source corpus ties the issue to 36 Siemens product SKUs across IEC and UL product families and recommends upgrading to V2.135 or later. For commissioned chargers connected to Siemens Device Management, the update may be delivered OTA.

Defensive priority

High. The issue is network-adjacent, requires no privileges or user interaction, and can enable direct device control. In OT and EV charging environments, that combination warrants prompt remediation and access restriction until patched.

Recommended defensive actions

  • Update affected Siemens chargers to V2.135 or later as recommended by the vendor.
  • If devices are fully commissioned and connected to Siemens Device Management, verify that the OTA update path is available and completed.
  • Restrict access to charging-network segments so only necessary management hosts can reach the devices.
  • Review whether Modbus must remain enabled on the local network; if not required, disable or segment it according to vendor guidance and site policy.
  • Validate which of the listed Siemens product SKUs are deployed before scheduling maintenance and remediation.
  • Monitor for unauthorized local-network traffic to charger management services and document any unexpected Modbus use.

Evidence notes

The summary is based on the supplied CISA CSAF advisory ICSA-25-135-08 and its Siemens references. The advisory states that affected devices contain Modbus service enabled by default and that a same-network attacker could remotely control the EV charger. The timeline and publication date supplied with the source are 2025-05-13, and no KEV entry is present in the provided enrichment data.

Official resources

Publicly disclosed on 2025-05-13 in CISA advisory ICSA-25-135-08 and Siemens security advisories. The provided enrichment data indicates the CVE is not listed in CISA KEV.