NVD / CVE Program· CNA siemens

CVE-2021-40358: A vulnerability has been identified in SIMATIC PCS 7 V8.2 (All versions), SIMATIC PCS 7 V9.0 (All versions < V9.0 SP3 UC04), SIMATIC PCS 7 V

Noroxi assessment

Priority: Monitor (action score 39/100)

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: 1.2% (FIRST EPSS); higher than 69.9% of all records.
Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
According to the record, no fixed version is available yet.
Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

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 PCS 7 V8.2 (All versions), SIMATIC PCS 7 V9.0 (All versions < V9.0 SP3 UC04), SIMATIC PCS 7 V9.1 (All versions < V9.1 SP1), SIMATIC WinCC V15 and earlier (All versions < V15 SP1 Update 7), SIMATIC WinCC V16 (All versions < V16 Update 5), SIMATIC WinCC V17 (All versions < V17 Update 2), SIMATIC WinCC V7.4 (All versions < V7.4 SP1 Update 19), SIMATIC WinCC V7.5 (All versions < V7.5 SP2 Update 5). Legitimate file operations on the web server of the affected systems do not properly neutralize special elements within the pathname. An attacker could then cause the pathname to resolve to a location outside of the restricted directory on the server and read, write or delete unexpected critical files.

CriticalCVSS 9.9 · v3.1—No exploit No fix recorded

Path traversal

Published: Nov 9, 2021
Updated: Jun 17, 2026
EPSS: 1.2% · 69th percentile
CWE: CWE-22

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 39 / 40 · 9.9 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 1.2%

CNA vs NVD score

NVD: —
CNA · siemens: 9.9; NVD has not scored this yet; the score shown is the CNA’s.

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/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

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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 pcs 7	cpe:2.3:a:siemens:simatic_pcs_7
siemens	simatic wincc	cpe:2.3:a:siemens:simatic_wincc

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

siemens simatic pcs 78.2
siemens simatic pcs 79.0
siemens simatic pcs 79.1
siemens simatic wincc15
siemens simatic wincc15.1
siemens simatic wincc16
siemens simatic wincc17
siemens simatic wincc7.4
siemens simatic wincc7.5

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 PCS 7 V8.2
- All versionsaffected
Siemens SIMATIC PCS 7 V9.0
- All versions < V9.0 SP3 UC04affected
Siemens SIMATIC PCS 7 V9.1
- All versions < V9.1 SP1affected
Siemens SIMATIC WinCC V15 and earlier
- All versions < V15 SP1 Update 7affected
Siemens SIMATIC WinCC V16
- All versions < V16 Update 5affected
Siemens SIMATIC WinCC V17
- All versions < V17 Update 2affected
Siemens SIMATIC WinCC V7.4
- All versions < V7.4 SP1 Update 19affected
Siemens SIMATIC WinCC V7.5
- All versions < V7.5 SP2 Update 5affected

Same product

siemens: all records

Other highest-scoring records for the same primary product.

CVE-2014-8551The WinCC server in Siemens SIMATIC WinCC 7.0 through SP3, 7.2 before Update 9, and 7.3 before Update 2; SIMATIC PCS 7 7.1 through SP4, 8.0
42Plan
CVE-2019-10922A vulnerability has been identified in SIMATIC PCS 7 V8.0 and earlier (All versions), SIMATIC PCS 7 V8.1 and newer (All versions), SIMATIC W
40Plan
CVE-2019-10918A vulnerability has been identified in SIMATIC PCS 7 V8.0 and earlier (All versions), SIMATIC PCS 7 V8.1 (All versions < V8.1 with WinCC V7.
36Monitor

Published before and after this one in the same product

← EarlierCVE-2020-7586Jun 10, 2020 · A vulnerability has been identified in SIMATIC PCS 7 V8.2 and earlier (All versions), SIMATIC PCS 7 V9.0 (All versions < V9.0 SP3), SIMATIC
31Monitor
← EarlierCVE-2020-10048Feb 9, 2021 · A vulnerability has been identified in SIMATIC PCS 7 (All versions), SIMATIC WinCC (All versions < V7.5 SP2).
22Monitor
Later →CVE-2021-40364Nov 9, 2021 · A vulnerability has been identified in SIMATIC PCS 7 V8.2 (All versions), SIMATIC PCS 7 V9.0 (All versions < V9.0 SP3 UC04), SIMATIC PCS 7 V
22Monitor

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).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

TR-21-0917 · Nov 12, 2021(Siemens Güvenlik Güncellemesi)

All national notices →

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
A low-privileged account is enough.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: high · data can be read
Integrity: high · data or configuration can be modified
Availability: high · the service can be disrupted

Impact can extend beyond the vulnerable component (scope changes).

Attack vector: Network
Attack complexity: Low
Privileges required: Low
User interaction: None
Scope: Changed
Confidentiality impact: High
Integrity impact: High
Availability impact: High

Weakness class (CWE)

CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

nvd-secondary

Root cause

A user-supplied file name is joined with the allowed directory, but the result is never checked to confirm it is still inside that directory.

The bug in code

The whole CWE-22 class

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

Vulnerable

1const file = path.join(ROOT, req.query.name);
2res.sendFile(file);

Fixed

1const file = path.resolve(ROOT, req.query.name);
2if (!file.startsWith(ROOT + path.sep)) {
3  return res.sendStatus(400);
4}
5res.sendFile(file);

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)

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/pdf/ssa-840188.pdf

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

All records