No exploitation reportedFix available

CVE-2021-42020

Q: Is CVE-2021-42020 actively exploited?

Active exploitation of CVE-2021-42020 has not been confirmed. Its EPSS score was 1.0% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2021-42020?

CVE-2021-42020 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.

No exploitation reported by the sources we read.

Published2022-03-08
Fixed in5.6.0
WeaknessCWE-754

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 RUGGEDCOM i800, RUGGEDCOM i800NC, RUGGEDCOM i801, RUGGEDCOM i801NC, RUGGEDCOM i802, RUGGEDCOM i802NC, RUGGEDCOM i803, RUGGEDCOM i803NC, RUGGEDCOM M2100, RUGGEDCOM M2100NC, RUGGEDCOM M2200, RUGGEDCOM M2200NC, RUGGEDCOM M969, RUGGEDCOM M969NC, RUGGEDCOM RMC30, RUGGEDCOM RMC30NC, RUGGEDCOM RMC8388 V4.X, RUGGEDCOM RMC8388 V5.X, RUGGEDCOM RMC8388NC V4.X, RUGGEDCOM RMC8388NC V5.X, RUGGEDCOM RP110, RUGGEDCOM RP110NC, RUGGEDCOM RS1600, RUGGEDCOM RS1600F, RUGGEDCOM RS1600FNC, RUGGEDCOM RS1600NC, RUGGEDCOM RS1600T, RUGGEDCOM RS1600TNC, RUGGEDCOM RS400, RUGGEDCOM RS400NC, RUGGEDCOM RS401, RUGGEDCOM RS401NC, RUGGEDCOM RS416, RUGGEDCOM RS416NC, RUGGEDCOM RS416NCv2 V4.X, RUGGEDCOM RS416NCv2 V5.X, RUGGEDCOM RS416P, RUGGEDCOM RS416PNC, RUGGEDCOM RS416PNCv2 V4.X, RUGGEDCOM RS416PNCv2 V5.X, RUGGEDCOM RS416Pv2 V4.X, RUGGEDCOM RS416Pv2 V5.X, RUGGEDCOM RS416v2 V4.X, RUGGEDCOM RS416v2 V5.X, RUGGEDCOM RS8000, RUGGEDCOM RS8000A, RUGGEDCOM RS8000ANC, RUGGEDCOM RS8000H, RUGGEDCOM RS8000HNC, RUGGEDCOM RS8000NC, RUGGEDCOM RS8000T, RUGGEDCOM RS8000TNC, RUGGEDCOM RS900, RUGGEDCOM RS900 (32M) V4.X, RUGGEDCOM RS900 (32M) V5.X, RUGGEDCOM RS900G, RUGGEDCOM RS900G (32M) V4.X, RUGGEDCOM RS900G (32M) V5.X, RUGGEDCOM RS900GNC, RUGGEDCOM RS900GNC(32M) V4.X, RUGGEDCOM RS900GNC(32M) V5.X, RUGGEDCOM RS900GP, RUGGEDCOM RS900GPNC, RUGGEDCOM RS900L, RUGGEDCOM RS900LNC, RUGGEDCOM RS900M-GETS-C01, RUGGEDCOM RS900M-GETS-XX, RUGGEDCOM RS900M-STND-C01, RUGGEDCOM RS900M-STND-XX, RUGGEDCOM RS900MNC-GETS-C01, RUGGEDCOM RS900MNC-GETS-XX, RUGGEDCOM RS900MNC-STND-XX, RUGGEDCOM RS900MNC-STND-XX-C01, RUGGEDCOM RS900NC, RUGGEDCOM RS900NC(32M) V4.X, RUGGEDCOM RS900NC(32M) V5.X, RUGGEDCOM RS900W, RUGGEDCOM RS910, RUGGEDCOM RS910L, RUGGEDCOM RS910LNC, RUGGEDCOM RS910NC, RUGGEDCOM RS910W, RUGGEDCOM RS920L, RUGGEDCOM RS920LNC, RUGGEDCOM RS920W, RUGGEDCOM RS930L, RUGGEDCOM RS930LNC, RUGGEDCOM RS930W, RUGGEDCOM RS940G, RUGGEDCOM RS940GNC, RUGGEDCOM RS969, RUGGEDCOM RS969NC, RUGGEDCOM RSG2100, RUGGEDCOM RSG2100 (32M) V4.X, RUGGEDCOM RSG2100 (32M) V5.X, RUGGEDCOM RSG2100NC, RUGGEDCOM RSG2100NC(32M) V4.X, RUGGEDCOM RSG2100NC(32M) V5.X, RUGGEDCOM RSG2100P, RUGGEDCOM RSG2100P (32M) V4.X, RUGGEDCOM RSG2100P (32M) V5.X, RUGGEDCOM RSG2100PNC, RUGGEDCOM RSG2100PNC (32M) V4.X, RUGGEDCOM RSG2100PNC (32M) V5.X, RUGGEDCOM RSG2200, RUGGEDCOM RSG2200NC, RUGGEDCOM RSG2288 V4.X, RUGGEDCOM RSG2288 V5.X, RUGGEDCOM RSG2288NC V4.X, RUGGEDCOM RSG2288NC V5.X, RUGGEDCOM RSG2300 V4.X, RUGGEDCOM RSG2300 V5.X, RUGGEDCOM RSG2300NC V4.X, RUGGEDCOM RSG2300NC V5.X, RUGGEDCOM RSG2300P V4.X, RUGGEDCOM RSG2300P V5.X, RUGGEDCOM RSG2300PNC V4.X, RUGGEDCOM RSG2300PNC V5.X, RUGGEDCOM RSG2488 V4.X, RUGGEDCOM RSG2488 V5.X, RUGGEDCOM RSG2488NC V4.X, RUGGEDCOM RSG2488NC V5.X, RUGGEDCOM RSG907R, RUGGEDCOM RSG908C, RUGGEDCOM RSG909R, RUGGEDCOM RSG910C, RUGGEDCOM RSG920P V4.X, RUGGEDCOM RSG920P V5.X, RUGGEDCOM RSG920PNC V4.X, RUGGEDCOM RSG920PNC V5.X, RUGGEDCOM RSL910, RUGGEDCOM RSL910NC, RUGGEDCOM RST2228, RUGGEDCOM RST2228P, RUGGEDCOM RST916C, RUGGEDCOM RST916P. The third-party component, in its TFTP functionality fails to check for null terminations in file names. If an attacker were to exploit this, it could result in data corruption, and possibly a hard-fault of the application.

Timeline

dates in UTC

2022-03-0812:15CVE 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-2021-42020?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-42020?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Siemens ruggedcom rosversion to verify

Branch	Affected	Fixed in	Source
5.6	< 5.6.0	5.6.0	NVD
—	all versions	no fix published	NVD

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-22-069-12 CISA136 known affected
Siemens RUGGEDCOM ROS
RUGGEDCOM i800 · RUGGEDCOM i800NC · RUGGEDCOM i801 · +133 more

Full record on NVD

Fix

Update Siemens ruggedcom ros to 5.6.0
Vendor fix CISA ICSA-22-069-12 · 51 productsUpdate to V4.3.8 or later version
Vendor fix CISA ICSA-22-069-12 · 21 productsUpdate to V5.6.0 or later version
Mitigation from the vendor CISA ICSA-22-069-12 · 136 productsRestrict web server access in affected system(s) to ports 443/TCP and 22/TCP, to trusted IP addresses only
Mitigation from the vendor CISA ICSA-22-069-12 · 136 productsRestrict access to port 69/UDP to trusted IP addresses only, for the TFTP vulnerability

Advisories and patches

cert-portal.siemens.comPatch · Vendor Advisory

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

CNACVSS 3.17.5read 2026-10-23
NVDCVSS 3.17.5read 2026-10-23
NVDCVSS 2.05read 2026-10-23
CNAweakness (CWE)CWE-754read 2026-10-23
NVDweakness (CWE)CWE-754read 2026-10-23
FIRST EPSSEPSS score1.0 %2026-10-23

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: 2022-03-08
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2021-42020?

Is CVE-2021-42020 actively exploited?

Active exploitation of CVE-2021-42020 has not been confirmed. Its EPSS score was 1.0% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-42020?

CVE-2021-42020 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.

Running RUGGEDCOM i800? Hear about its next vulnerability

Surveillance reads the versions in your stack — a domain, a lockfile or a list — checks each CVE against the ranges its sources publish, and alerts you when one you run is exploited or enters CISA KEV. A version it cannot read stays « version not verified ».

Get alerts for this product CISA KEV additions, October 2026 Search CVEs

No credit card required · No monthly cap on website lookups · 250 API requests/month

Go further

Following what attackers exploit right now? The CISA KEV additions of the month, with their patch deadlines.
Running this software? Vulnerability monitoring alerts you to new vulnerabilities in your products.

Related vulnerabilities

Same product first, then the same vendor advisory and the same publication week.

Back to CVE Database