Vulnerability Snapshot
CVE-2020-28221 is rated CRITICAL — exploitation is trivial or already observed in the wild and impact is severe. Patch immediately, not on the next maintenance window.
Affected technology: ecostruxure_operator_terminal_expert, hmi_sto_501, hmi_sto_511, hmi_sto_512, hmi_sto_531, plus 5 other product variants.
Executive Summary
A CWE-20: Improper Input Validation vulnerability exists in EcoStruxure™ Operator Terminal Expert and Pro-face BLUE (version details in the notification) that could cause arbitrary code execution when the Ethernet Download feature is enable on the HMI.
Why It Matters
CVE-2020-28221 is rated CRITICAL severity, requiring immediate attention from security teams.
CVSS Base Score: 9.8/10
Affected Technologies
Vendors: schneider-electric
Products: ecostruxure_operator_terminal_expert, hmi_sto_501, hmi_sto_511, hmi_sto_512, hmi_sto_531, hmi_sto_532, hmig3u, hmig3x, hmig5u, hmig5u2, hmist6200, hmist6400, hmist6500, hmist6600, hmist6700, pro-face_blue, gp-4104g, gp-4104w, gp-4105g, gp-4105w, gp-4106g, gp-4106w, gp-4107g, gp-4107w, sp-5400wa, sp-5500tp, sp-5500wa, sp-5600ta, sp-5600tp, sp-5600wa, sp-5660tp, sp-5700tp, sp-5700wc, sp-5800wc, sp-5b00, sp-5b10, sp-5b41, st-6200wa, st-6400wa, st-6500wa, st-6600wa, st-6700wa
🛡️What Defenders Should Check
Use Vulnios to continuously monitor your exposure to CVE-2020-28221 and similar vulnerabilities.
References & Sources
How Vulnios Detects This
Vulnios scans for this vulnerability using Trivy and Grype for SBOM-based CVE matching and Vulnios CVE feed continuous monitoring against your asset inventory. Run a scan against your environment to see whether you are exposed; findings are linked back to the original CVE record so triage starts with the patch path already known.
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Affected Products
Sources
Related Threat Alerts
- Critical Vulnerability: CVE-2020-7540 — schneider-electric — modicon_m340_bmxp341000_firmware, modicon_m340_bmxp341000
- Critical Vulnerability: CVE-2020-28215 — schneider-electric — easergy_t300_firmware, easergy_t300
- Critical Vulnerability: CVE-2020-7561 — schneider-electric — easergy_t300_firmware, easergy_t300
- Critical Vulnerability: CVE-2020-7548 — schneider-electric — acti9_smartlink_si_d_firmware, acti9_smartlink_si_d
- Critical Vulnerability: CVE-2020-7533 — schneider-electric — modicon_m340_bmxp3420302_firmware, modicon_m340_bmxp3420302
- Critical Vulnerability: CVE-2020-28212 — schneider-electric — ecostruxure_control_expert
Frequently Asked Questions
What is CVE-2020-28221?
CVE-2020-28221 is a critical-severity vulnerability tracked under the Common Vulnerabilities and Exposures program. A CWE-20: Improper Input Validation vulnerability exists in EcoStruxure™ Operator Terminal Expert and Pro-face BLUE (version details in the notification) that could cause arbitrary code execution when
Am I affected?
Check whether your environment runs ecostruxure_operator_terminal_expert, hmi_sto_501, hmi_sto_511, hmi_sto_512, hmi_sto_531. If you operate any of those, treat yourself as in scope until you have evidence otherwise. A Vulnios scan will identify the exact assets carrying the affected version.
How urgent is the response?
Critical: do not wait for your normal patch cycle. Verify exposure today, apply the vendor patch immediately, and add detection rules for any post-exploit indicators.
How do I remediate?
Apply the vendor patch listed in the upstream advisory linked under Sources. If the patch is not yet available, follow the vendor-supplied workaround (often a config flag or feature disable) and add detections for the published exploit pattern in your SIEM. Re-scan after the patch lands to confirm the finding clears.
Where can I track exploitation activity?
Watch CISA's Known Exploited Vulnerabilities catalog for CVE-2020-28221. Cross-reference with public exploit databases and your own SIEM/IDS for indicator-of-compromise patterns. Vulnios tracks KEV status automatically and surfaces it on the asset findings view.
How does Vulnios help with this?
Vulnios continuously cross-references your asset inventory against the live CVE feed (NVD, vendor advisories, CISA KEV, and curated OSINT). When a new CVE matches your environment, you get a prioritized finding with the severity, KEV status, exploit-prediction (EPSS), and a direct path to the vendor patch. You can start a free scan from the homepage.
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