CVE-2017-9938: siemens simatic_logon Out-of-bounds Write
Vulnerability summary
CVE-2017-9938 is a high (CVSS 7.5) Out-of-bounds Write vulnerability in siemens simatic_logon. EPSS estimates a 2.90% chance of exploitation in the next 30 days, higher than 86.9% of scored vulnerabilities.
Severe, CVSS 7.5 (NVD); no exploitation reported by the 5 checked sources; EPSS 3% (FIRST, 03-11-2026)
Source freshness unavailable
How is this decided?Timeline
- 08-08-2017PublishedVulnerability first disclosed.
- 05-08-2024Last modifiedVulnerability information updated.
Description
A vulnerability was discovered in Siemens SIMATIC Logon (All versions before V1.6) that could allow specially crafted packets sent to the SIMATIC Logon Remote Access service on port 16389/tcp to cause a Denial-of-Service condition. The service restarts automatically.
CVSS metrics
2 scores · 1 source · 2 versionsEPSS trend
Probability
2.90%
Chance of exploitation in the next 30 days
Percentile
87%
Versus all other CVEs
30-day change
No change 0.00 pp
From 2.90% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-787Out-of-bounds WriteThe product writes data past the end, or before the beginning, of the intended buffer.
- CWE-20Improper Input ValidationThe product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
Affected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Siemens1 product
- simatic_logon≤ 1.5
1 vendor · 1 product
References
3 links- www.tenable.com/security/research/tra-2017-34X Refsource MISC
- www.siemens.com/cert/pool/cert/siemens_security_advisory_ssa-804859.pdfX Refsource CONFIRMVendor Advisory