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CVE-2025-27540 Siemens CVE debrief

CVE-2025-27540 is a critical SQL injection issue in Siemens TeleControl Server Basic. According to the advisory, a remote unauthenticated attacker who can reach TCP port 8000 may bypass authorization controls, read and write the application database, and execute code as NT AUTHORITY\NetworkService. Siemens lists an update to V3.1.2.2 or later and access restriction for port 8000 as the primary mitigations.

Vendor
Siemens
Product
TeleControl Server Basic
CVSS
CRITICAL 9.8
CISA KEV
Not listed in stored evidence
Original CVE published
2025-04-16
Original CVE updated
2025-05-06
Advisory published
2025-04-16
Advisory updated
2025-05-06

Who should care

OT/ICS defenders, Siemens TeleControl Server Basic administrators, network/security teams protecting systems exposed on TCP/8000, and any organization running the affected product in a reachable network segment.

Technical summary

The vulnerability is described as SQL injection in the internally used Authenticate method. The impact stated in the advisory includes authorization bypass, database read/write access, and remote code execution with NT AUTHORITY\NetworkService permissions. The attack requires network access to port 8000 on a system running a vulnerable version of the application.

Defensive priority

Critical — prioritize immediate patching or, if patching is not yet possible, restrict exposure of TCP/8000 to trusted sources only.

Recommended defensive actions

  • Update Siemens TeleControl Server Basic to V3.1.2.2 or later.
  • Restrict access to TCP port 8000 on affected systems to trusted IP addresses only.
  • Inventory all TeleControl Server Basic deployments and confirm whether any instances are reachable from untrusted networks.
  • Review Siemens advisory guidance and CISA ICS recommended practices for additional hardening and network segmentation steps.

Evidence notes

Primary evidence comes from the CISA CSAF advisory ICSA-25-112-01 and Siemens product security notice SSA-443402. The supplied advisory text states the SQL injection location (Authenticate), the required network access condition (port 8000), the impact (authorization bypass, database access, and code execution as NT AUTHORITY\NetworkService), and the vendor remediation (V3.1.2.2 or later plus access restriction to port 8000).

Sources and references

Verified primary and authoritative sources

  • CVE-2025-27540 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2025-27540

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2025-27540 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2025-27540

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • Source item URL

    Unverified legacy reference

    URL: https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/OT/white/2025/icsa-25-112-01.json

    cisa_csaf

  • Source reference

    Unverified legacy reference

    URL: https://cert-portal.siemens.com/productcert/csaf/ssa-443402.json

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://cert-portal.siemens.com/productcert/html/ssa-443402.html

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/news-events/ics-advisories/icsa-25-112-01

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/uscert/ics/alerts/ICS-ALERT-10-301-01

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/resources-tools/resources/ics-recommended-practices

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/topics/industrial-control-systems

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://us-cert.cisa.gov/sites/default/files/recommended_practices/NCCIC_ICS-CERT_Defense_in_Depth_2016_S508C.pdf

    Reference

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.