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NVD / CVE Program· CNA siemens

CVE-2021-44695: Affected devices don't process correctly certain special crafted packets sent to port 102/tcp, which could allow an attacker to cause a deni

Noroxi assessment

Priority: Monitor (action score 19/100)

  • 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: 0.76% (FIRST EPSS); higher than 55.5% of all records.
  • Anyone who can reach it over the internet can trigger it. Administrator privileges are required. No user action is 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

Affected devices don't process correctly certain special crafted packets sent to port 102/tcp, which could allow an attacker to cause a denial of service in the device.

MediumCVSS 4.9 · v3.1—No exploit No fix recorded
Published
Dec 13, 2022
Updated
Jun 17, 2026
EPSS
0.7% · 55th percentile

Report tools

JSON

Action score

19

Monitor

Low priority for now.

CVSS
19 / 40 · 4.9 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.7%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · siemens
4.9
NVD has not scored this yet; the score shown is the CNA’s.

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

Follow CVE-2021-44695

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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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.

VendorProduct
siemenssimatic s7-plcsim advanced firmware
siemenssimatic s7-plcsim advanced
siemenssimatic s7-1200 cpu 1211c firmware
siemenssimatic s7-1200 cpu 1211c
siemenssimatic s7-1200 cpu 1212c firmware
siemenssimatic s7-1200 cpu 1212c
siemenssimatic s7-1200 cpu 1212fc firmware
siemenssimatic s7-1200 cpu 1212fc
siemenssimatic s7-1200 cpu 1214 fc firmware
siemenssimatic s7-1200 cpu 1214 fc
siemenssimatic s7-1200 cpu 1214c firmware
siemenssimatic s7-1200 cpu 1214c

and 180 more

Affected versions

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

  • siemens simatic et 200 sp open controller cpu 1515sp pc firmwareall versions
  • siemens simatic s7-1200 cpu 12 1211c firmwarebefore 4.6.0
  • siemens simatic s7-1200 cpu 12 1212c firmwarebefore 4.6.0
  • siemens simatic s7-1200 cpu 12 1212fc firmwarebefore 4.6.0
  • siemens simatic s7-1200 cpu 12 1214c firmwarebefore 4.6.0
  • siemens simatic s7-1200 cpu 12 1214fc firmwarebefore 4.6.0
  • siemens simatic s7-1200 cpu 12 1215c firmwarebefore 4.6.0
  • siemens simatic s7-1200 cpu 12 1215fc firmwarebefore 4.6.0
  • siemens simatic s7-1200 cpu 12 1217c firmwarebefore 4.6.0
  • siemens simatic s7-1200 cpu 1211c firmwarebefore 4.6.0
  • siemens simatic s7-1200 cpu 1212c firmwarebefore 4.6.0
  • siemens simatic s7-1200 cpu 1212fc firmwarebefore 4.6.0
  • siemens simatic s7-1200 cpu 1214 fc firmwarebefore 4.6.0
  • siemens simatic s7-1200 cpu 1214c firmwarebefore 4.6.0
  • siemens simatic s7-1200 cpu 1214fc firmwarebefore 4.6.0
  • siemens simatic s7-1200 cpu 1215 fc firmwarebefore 4.6.0
  • siemens simatic s7-1200 cpu 1215c firmwarebefore 4.6.0
  • siemens simatic s7-1200 cpu 1215fc firmwarebefore 4.6.0
  • siemens simatic s7-1200 cpu 1217c firmwarebefore 4.6.0
  • siemens simatic s7-1500 cpu 1507s f firmwarebefore 3.0.1

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 Drive Controller CPU 1504D TF

    • All versions < V2.9.7affected

  • Siemens SIMATIC Drive Controller CPU 1507D TF

    • All versions < V2.9.7affected

  • Siemens SIMATIC ET 200SP Open Controller CPU 1515SP PC2 (incl. SIPLUS variants)

    • All versions < V21.9.7affected

  • Siemens SIMATIC S7-1200 CPU family (incl. SIPLUS variants)

    • All versions < V4.6.0affected

  • Siemens SIMATIC S7-1500 CPU 1510SP F-1 PN

    • All versions < V2.9.7affected

  • Siemens SIMATIC S7-1500 CPU 1510SP-1 PN

    • All versions < V2.9.7affected

  • Siemens SIMATIC S7-1500 CPU 1511-1 PN

    • All versions < V2.9.7, All versions < V2.9.7affected

  • Siemens SIMATIC S7-1500 CPU 1511C-1 PN

    • All versions < V2.9.7, All versions < V2.9.7affected

  • Siemens SIMATIC S7-1500 CPU 1511F-1 PN

    • All versions < V2.9.7, All versions < V2.9.7affected

  • Siemens SIMATIC S7-1500 CPU 1511T-1 PN

    • All versions < V2.9.7affected

  • Siemens SIMATIC S7-1500 CPU 1511TF-1 PN

    • All versions < V2.9.7affected

  • Siemens SIMATIC S7-1500 CPU 1512C-1 PN

    • All versions < V2.9.7, All versions < V2.9.7affected

Same product

siemens: all records

Other highest-scoring records for the same primary product.

  • CVE-2021-40365Affected devices don't process correctly certain special crafted packets sent to port 102/tcp, which could allow an attacker to cause a deni
    30Monitor
  • CVE-2021-44694Affected devices don't process correctly certain special crafted packets sent to port 102/tcp, which could allow an attacker to cause a deni
    22Monitor
  • CVE-2021-44693Affected devices don't process correctly certain special crafted packets sent to port 102/tcp, which could allow an attacker to cause a deni
    19Monitor

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

  • Anyone who can reach it over the internet can trigger it.
  • Administrator privileges are required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
High
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-1286 · Improper Validation of Syntactic Correctness of Input

CVSS vector

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

nvd-secondary

Attack context

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

ATT&CK techniques

—

Change log

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

References

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

All records