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No exploitation reportedFix available

CVE-2018-16561

No exploitation reported by the sources we read.

  • Published2019-04-17
  • WeaknessCWE-20

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

A vulnerability has been identified in SIMATIC S7-300 CPUs (All versions < V3.X.16). The affected CPUs improperly validate S7 communication packets which could cause a Denial-of-Service condition of the CPU. The CPU will remain in DEFECT mode until manual restart. Successful exploitation requires an attacker to be able to send a specially crafted S7 communication packet to a communication interface of the CPU. This includes Ethernet, PROFIBUS, and Multi Point Interfaces (MPI). No user interaction or privileges are required to exploit the security vulnerability. The vulnerability could allow causing a Denial-of-Service condition of the core functionality of the CPU, compromising the availability of the system. At the time of advisory publication no public exploitation of this security vulnerability was known. Siemens confirms the security vulnerability and provides mitigations to resolve the security issue.

Timeline

dates in UTC
  1. 2019-04-1714:29CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2018-16561?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2018-16561?format=csv
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Versions per branch

NVD
Siemens simatic s7-300 firmwareversion to verify
BranchAffectedFixed in
—all versionsno fix published
Siemens simatic s7-300f firmwareversion to verify
BranchAffectedFixed in
—all versionsno fix published
Siemens simatic s7-300fs firmwareversion to verify
BranchAffectedFixed in
—all versionsno fix published

1 more product in the sources.

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Vendor advisories

  • ICSA-19-043-04 CISA1 known affected

    Siemens SIMATIC S7-300 CPU

    Siemens SIMATIC S7-300 CPU family (incl. related ET200 CPUs and SIPLUS variants): All versions < V3.X.16

Full record on NVD

Fix

  1. Vendor fix CISA ICSA-19-043-04 · 1 productUpdate to V3.X.16 or any later version https://support.industry.siemens.com/cs/ww/en/ps/13752/dl
  2. Mitigation from the vendor CISA ICSA-19-043-04 · 1 productSiemens recommends operating the devices only within trusted networks

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub

Sources

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published
2019-04-17
Last Modified
2026-06-17
NVD status
Modified

Frequently asked questions

What is CVE-2018-16561?

A vulnerability has been identified in SIMATIC S7-300 CPUs (All versions < V3.X.16). The affected CPUs improperly validate S7 communication packets which could cause a Denial-of-Service condition of the CPU. The CPU will remain in DEFECT mode until manual restart. Successful exploitation requires an attacker to be able to send a specially crafted S7 communication packet to a communication interface of the CPU. This includes Ethernet, PROFIBUS, and Multi Point Interfaces (MPI). No user interaction or privileges are required to exploit the security vulnerability. The vulnerability could allow causing a Denial-of-Service condition of the core functionality of the CPU, compromising the availability of the system. At the time of advisory publication no public exploitation of this security vulnerability was known. Siemens confirms the security vulnerability and provides mitigations to resolve the security issue.

Is CVE-2018-16561 actively exploited?

Active exploitation of CVE-2018-16561 has not been confirmed. Its EPSS score was 1.4% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2018-16561?

CVE-2018-16561 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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