Security readout for executives and security teams
Plain-English summary
This affects Siemens SIPROTEC 5 protection devices. A highly privileged authenticated user can upload arbitrary files through the DIGSI 5 protocol. Malicious configuration files could make devices unavailable and may lead to code execution. No active exploitation is stated in the supplied sources.
Executive priority
Prioritize review for substations or facilities where SIPROTEC 5 devices protect critical processes. This is not presented as internet-scale or actively exploited, but authenticated misuse could disrupt protection devices and create operational risk.
Technical view
CVE-2025-40808 is a CWE-434 arbitrary file upload issue in many SIPROTEC 5 CP050/CP100/CP150/CP200/CP300 variants, listed as all versions. CVSS v4.0 is 6.9 with adjacent attack vector and high privileges required. Reported impacts are high integrity and availability impact, with possible code execution.
Likely exposure
Exposure is most likely in operational technology environments using affected Siemens SIPROTEC 5 devices managed through DIGSI 5. The CVSS vector indicates adjacent network access and high privileges are required, so risk depends heavily on engineering workstation access, network segmentation, and account control.
Exploitation context
The supplied bundle does not show CISA KEV listing or other evidence of active exploitation. Exploitation requires authenticated high privileges and access to the relevant DIGSI 5 protocol path. Impact is still operationally important because protection-device denial of service can affect power-system reliability.
Researcher notes
Do not assume unauthenticated or remote internet exploitation from the supplied data. The key research questions are which DIGSI 5 upload paths accept arbitrary files, how malicious configurations trigger denial of service, and whether code execution is confirmed by Siemens guidance.
Mitigation direction
- Review Siemens ProductCERT SSA-139483 for official fixes, workarounds, and product-specific guidance.
- Restrict DIGSI 5 protocol access to trusted engineering workstations and management networks.
- Limit high-privileged SIPROTEC and DIGSI accounts to named operational roles.
- Audit and approve configuration uploads to affected SIPROTEC 5 devices.
- Monitor affected devices for unexpected configuration changes or availability issues.
Validation and detection
- Inventory SIPROTEC 5 models and CP variants against the affected product list.
- Confirm whether DIGSI 5 access is reachable only from segmented engineering networks.
- Review privileged account lists for users able to upload device configurations.
- Check configuration management logs for unusual uploads or unexplained device faults.
- Track Siemens advisory status for fixed versions or compensating controls.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-434: File access and web shell behavior lookup
File traversal and upload weaknesses can lead teams to review file, web shell, execution, and collection telemetry. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2025-40808 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 6.9 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:A/AC:L/AT:N/PR:H/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
2 official scoresWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:4.0/AV:A/AC:L/AT:N/PR:H/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N——siemensCVSS:3.1/AV:A/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H0.95.2siemensVulnerability scoring details
Base CVSS 4.0 score
6.9MediumVector: CVSS:4.0/AV:A/AC:L/AT:N/PR:H/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N
Base CVSS 3.1 score
6.1MediumVector: CVSS:3.1/AV:A/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://cert-portal.siemens.com/productcert/html/ssa-139483.htmlCVE reference, siemens
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Unrestricted Upload of File with Dangerous Type
Unrestricted Upload of File with Dangerous Type represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.