A vulnerability has been identified in RWG1.M12 (All versions < V1.16.16), RWG1.M12D (All versions < V1.16.16), RWG1.M8 (All versions < V1.…

published 2021-07-13 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-12563

cvss: 4.3; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 31%
public exploits: 0; none known

A vulnerability has been identified in RWG1.M12 (All versions < V1.16.16), RWG1.M12D (All versions < V1.16.16), RWG1.M8 (All versions < V1.16.16). Sending specially crafted ARP packets to an affected device could cause a partial denial-of-service, preventing the device to operate normally. A restart is needed to restore normal operations.

Patch / fix

fixed in 3 links 1

siemens rwg1.m12_firmware 1.16.16
siemens rwg1.m12d_firmware 1.16.16
siemens rwg1.m8_firmware 1.16.16

cert-portal.siemens.com/productcert/pdf/ssa-448291.pdf advisory

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

cisa ICSA-21-194-14 updated 2025-05-06 cvss 6.5

Siemens RWG Universal Controllers

Siemens RWG1.M8 <V1.16.16 Siemens RWG1.M12 <V1.16.16 Siemens RWG1.M12D <V1.16.16
affected: vendor fix, workaround ubc.siemens.com.cn

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

Exploit prediction

0.38% chance of exploitation in the next 30 days, higher than 31% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
NVD	3.1	4.3	CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
NVD	2.0	3.3	AV:A/AC:L/Au:N/C:N/I:N/A:P

Affected products

Siemens RWG1.M12
Siemens RWG1.M12D
Siemens RWG1.M8

Classification

Weakness

CWE-770 Allocation of Resources Without Limits or Throttling

References

cert-portal.siemens.com /productcert/pdf/ssa-448291.pdf
patch, vendor-advisory

Sources

CVE List CVE-2021-25671
NVD CVE-2021-25671

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary