Security readout for executives and security teams
Plain-English summary
Siemens engineering and HMI software can mishandle hardware configuration profiles and run attacker-controlled code inside the affected application. This mainly matters for organizations with Siemens TIA Portal, STEP 7, WinCC, drive, motor, or safety engineering workstations.
Executive priority
Treat this as a high-priority workstation and engineering-tool remediation item, especially in OT environments. It is not presented as internet-scale remote exploitation, but successful abuse could compromise trusted automation engineering software and downstream project integrity.
Technical view
CVE-2023-32735 is CWE-502 unsafe deserialization in Siemens applications using .NET BinaryFormatter for hardware configuration profiles. The reported outcome is type confusion leading to arbitrary code execution within the affected application. CVSS v4.0 is 7.0 with local access, high privileges, and user interaction required.
Likely exposure
Exposure is most likely on engineering workstations or operator engineering environments running affected Siemens SIMATIC STEP 7, STEP 7 Safety, WinCC, WinCC Unified, SIMOCODE ES, SIMOTION SCOUT TIA, SINAMICS Startdrive, SIRIUS tools, Soft Starter ES, or TIA Portal Cloud versions.
Exploitation context
The source bundle does not show active exploitation, and CISA KEV status is false. The CVSS vector indicates local access, high privileges, and user interaction, so this is not described as unauthenticated remote exploitation. Risk increases where project/profile files are exchanged or imported from untrusted sources.
Researcher notes
Focus validation on unsafe BinaryFormatter deserialization paths for hardware configuration profiles. Do not assume controller compromise from the CVE text alone; the stated impact is arbitrary code execution within the affected application. Evidence for exploitation in the wild is not provided.
Mitigation direction
- Review Siemens SSA-779936 for product-specific update guidance.
- Upgrade affected STEP 7 and WinCC versions to the fixed updates named by Siemens.
- Restrict use of hardware configuration profiles from untrusted sources.
- Prioritize engineering workstations that handle safety, HMI, and automation projects.
- Check Siemens guidance for affected products where no fixed version is named.
Validation and detection
- Inventory Siemens engineering tools and exact versions on workstations.
- Compare installed versions against the affected ranges in CVE-2023-32735.
- Confirm whether users import hardware configuration profiles from external sources.
- Verify patched products meet or exceed Siemens fixed update levels.
- Document exceptions for products listed as all versions affected.
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-502: Code execution behavior lookup
Code execution and unsafe deserialization weaknesses often justify reviewing execution behavior and process 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-2023-32735 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
- High
- CVSS
- 7 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:P/VC:H/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.
CVSS vector scores
1 official scoreWe 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:L/AC:L/AT:N/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N——Primary CVE scoreVulnerability scoring details
Base CVSS 4.0 score
7HighVector: CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Source materials
- CVE List V5 sourceCVE List V5
- https://cert-portal.siemens.com/productcert/html/ssa-779936.htmlCVE reference
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.
Deserialization of Untrusted Data
Deserialization of Untrusted Data represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.