NVD / CVE Program· CNA siemens

CVE-2023-32735: A vulnerability has been identified in SIMATIC STEP 7 Safety V16 (All versions < V16 Update 7), SIMATIC STEP 7 Safety V17 (All versions < V1

Noroxi assessment

Priority: Monitor (action score 28/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.21% (FIRST EPSS).
Someone with local access to the system can trigger it. Administrator privileges are required. No special conditions are required; it is repeatable.
According to the record, no fixed version is available yet.

Low priority for now. Update when a fix is released; follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

A vulnerability has been identified in SIMATIC STEP 7 Safety V16 (All versions < V16 Update 7), SIMATIC STEP 7 Safety V17 (All versions < V17 Update 7), SIMATIC STEP 7 Safety V18 (All versions < V18 Update 2), SIMATIC STEP 7 V16 (All versions < V16 Update 7), SIMATIC STEP 7 V17 (All versions < V17 Update 7), SIMATIC STEP 7 V18 (All versions < V18 Update 2), SIMATIC WinCC Unified V16 (All versions < V16 Update 7), SIMATIC WinCC Unified V17 (All versions < V17 Update 7), SIMATIC WinCC Unified V18 (All versions < V18 Update 2), SIMATIC WinCC V16 (All versions < V16.7), SIMATIC WinCC V17 (All versions < V17.7), SIMATIC WinCC V18 (All versions < V18 Update 2), SIMOCODE ES V16 (All versions < V16 Update 7), SIMOCODE ES V17 (All versions < V17 Update 7), SIMOCODE ES V18 (All versions < V18 Update 2), SIMOTION SCOUT TIA V5.4 SP1 (All versions), SIMOTION SCOUT TIA V5.4 SP3 (All versions), SIMOTION SCOUT TIA V5.5 SP1 (All versions), SINAMICS Startdrive V16 (All versions), SINAMICS Startdrive V17 (All versions), SINAMICS Startdrive V18 (All versions), SIRIUS Safety ES V17 (All versions < V17 Update 7), SIRIUS Safety ES V18 (All versions < V18 Update 2), SIRIUS Soft Starter ES V17 (All versions < V17 Update 7), SIRIUS Soft Starter ES V18 (All versions < V18 Update 2), Soft Starter ES V16 (All versions < V16 Update 7), TIA Portal Cloud V3.0 (All versions < V18 Update 2). Affected applications do not properly restrict the .NET BinaryFormatter when deserializing hardware configuration profiles. This could allow an attacker to cause a type confusion and execute arbitrary code within the affected application. This is the same issue that exists for .NET BinaryFormatter https://docs.microsoft.com/en-us/visualstudio/code-quality/ca2300.

HighCVSS 7.0 · v4.0—No exploit No fix recorded

Deserialization

BDU:2024-05635

Published: Jul 9, 2024
Updated: Jun 17, 2026
EPSS: 0.2% · 11th percentile
CWE: CWE-502

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 28 / 40 · 7.0 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.2%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · siemens: 6.5; NVD has not scored this yet; the score shown is the CNA’s.

CVSS:3.1/AV:L/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
siemens	simatic step 7 safety	cpe:2.3:a:siemens:simatic_step_7_safety
siemens	simatic step 7	cpe:2.3:a:siemens:simatic_step_7
siemens	simatic wincc unified	cpe:2.3:a:siemens:simatic_wincc_unified
siemens	simatic wincc	cpe:2.3:a:siemens:simatic_wincc
siemens	simocode es	cpe:2.3:a:siemens:simocode_es
siemens	simotion scout tia	cpe:2.3:a:siemens:simotion_scout_tia
siemens	sinamics startdrive	cpe:2.3:a:siemens:sinamics_startdrive
siemens	sirius safety es	cpe:2.3:a:siemens:sirius_safety_es
siemens	sirius soft starter es	cpe:2.3:a:siemens:sirius_soft_starter_es
siemens	soft starter es	cpe:2.3:a:siemens:soft_starter_es
siemens	tia portal cloud v3.0	cpe:2.3:a:siemens:tia_portal_cloud_v3.0

Versions reported by the vendor

Affected version ranges reported by the assigning authority (siemens). Independent of NVD's CPE analysis and usually ahead of it.

Siemens SIMATIC STEP 7 Safety V16
- before V16 Update 7affected
Siemens SIMATIC STEP 7 Safety V17
- before V17 Update 7affected
Siemens SIMATIC STEP 7 Safety V18
- before V18 Update 2affected
Siemens SIMATIC STEP 7 V16
- before V16 Update 7affected
Siemens SIMATIC STEP 7 V17
- before V17 Update 7affected
Siemens SIMATIC STEP 7 V18
- before V18 Update 2affected
Siemens SIMATIC WinCC Unified V16
- before V16 Update 7affected
Siemens SIMATIC WinCC Unified V17
- before V17 Update 7affected
Siemens SIMATIC WinCC Unified V18
- before V18 Update 2affected
Siemens SIMATIC WinCC V16
- before V16.7affected
Siemens SIMATIC WinCC V17
- before V17.7affected
Siemens SIMATIC WinCC V18
- before V18 Update 2affected

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

Someone with local access to the system can trigger it.
Administrator privileges are required.
No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability

Attack vector: Local
Attack complexity: Low
Privileges required: High
User interaction: P
Scope: X

Weakness class (CWE)

CWE-502 · Deserialization of Untrusted Data

CVSS 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

nvd-secondary

Root cause

Data received over the network is deserialized into the language’s native object format without verifying its source. Code paths inside the object can be triggered during deserialization.

The bug in code

The whole CWE-502 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

python

1payload = sock.recv(65536)
2job = pickle.loads(payload)

Fixed

python

1payload = sock.recv(65536)
2if not hmac.compare_digest(sign(payload), header_sig):
3    raise PermissionError("invalid signature")
4job = JobSchema.validate(json.loads(payload))

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

Object InjectionCAPEC-586likelihood: Medium · High

ATT&CK techniques

—

Change log

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

cert-portal.siemens.com/productcert/html/ssa-779936.html

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

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