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PatchSiren cyber security CVE debrief

CVE-2025-27539 Siemens CVE debrief

CVE-2025-27539 is a critical SQL injection issue in Siemens TeleControl Server Basic. According to the CISA/Siemens advisory, an unauthenticated remote attacker who can reach port 8000 on a vulnerable system may bypass authorization, read and write the application's database, and potentially execute code as NT AUTHORITY\NetworkService. The advisory was published on 2025-04-16 and later revised on 2025-05-06 for typo fixes.

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

Organizations operating Siemens TeleControl Server Basic, especially deployments with port 8000 reachable from untrusted networks. OT/ICS security teams, system owners, and administrators responsible for patching or network restriction should treat this as high priority.

Technical summary

The issue is described as SQL injection in the internally used VerifyUser method. The exposed attack path is network-based and requires no authentication. Impact includes authorization bypass, database read/write access, and code execution with NT AUTHORITY\NetworkService permissions. The affected product is Siemens TeleControl Server Basic, and the vendor remediation specifies updating to V3.1.2.2 or later; interim mitigation is to restrict access to port 8000 to trusted IP addresses.

Defensive priority

Critical. The CVSS 3.1 vector is 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H), and the advisory describes unauthenticated remote impact with potential code execution. Prioritize patching or strict network access control immediately.

Recommended defensive actions

  • Update Siemens TeleControl Server Basic to V3.1.2.2 or later.
  • Restrict access to port 8000 on affected systems to trusted IP addresses only.
  • Identify all TeleControl Server Basic deployments and confirm whether any are reachable from untrusted networks.
  • Review segmentation and firewall rules around OT/ICS management interfaces exposed to port 8000.
  • Validate remediation after patching and monitor for unexpected access attempts against the service.

Evidence notes

The supplied source corpus is a CISA CSAF advisory (ICSA-25-112-01) for CVE-2025-27539, referencing Siemens advisory SSA-443402. The advisory text states the VerifyUser SQL injection impact and the port 8000 access requirement. Publication date is 2025-04-16, with a revision on 2025-05-06 that only fixed typos. The supplied enrichment marks this as not a KEV-listed vulnerability.

Sources and references

Verified primary and authoritative sources

  • CVE-2025-27539 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2025-27539

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

  • CVE-2025-27539 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2025-27539

    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.