CVE-2021-27384

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.8 under NVD CVSS v3. EPSS exploit probability: 1.9%, top 16% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
9.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 3%CVSS: 9.8Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

A vulnerability has been identified in SIMATIC HMI Comfort Outdoor Panels V15 7\" & 15\" (incl. SIPLUS variants) (All versions < V15.1 Update 6), SIMATIC HMI Comfort Outdoor Panels V16 7\" & 15\" (incl. SIPLUS variants) (All versions < V16 Update 4), SIMATIC HMI Comfort Panels V15 4\" - 22\" (incl. SIPLUS variants) (All versions < V15.1 Update 6), SIMATIC HMI Comfort Panels V16 4\" - 22\" (incl. SIPLUS variants) (All versions < V16 Update 4), SIMATIC HMI KTP Mobile Panels V15 KTP400F, KTP700, KTP700F, KTP900 and KTP900F (All versions < V15.1 Update 6), SIMATIC HMI KTP Mobile Panels V16 KTP400F, KTP700, KTP700F, KTP900 and KTP900F (All versions < V16 Update 4), SIMATIC WinCC Runtime Advanced V15 (All versions < V15.1 Update 6), SIMATIC WinCC Runtime Advanced V16 (All versions < V16 Update 4), SINAMICS GH150 (All versions), SINAMICS GL150 (with option X30) (All versions), SINAMICS GM150 (with option X30) (All versions), SINAMICS SH150 (All versions), SINAMICS SL150 (All versions), SINAMICS SM120 (All versions), SINAMICS SM150 (All versions), SINAMICS SM150i (All versions). SmartVNC has an out-of-bounds memory access vulnerability in the device layout handler, represented by a binary data stream on client side, which can potentially result in code execution.

CVSS v3
9.8
EG Score
9.8(medium)
EPSS
83.3%
KEV
Not listed

Published

May 12, 2021

Last Modified

June 2, 2026

Advisory Details (1)

Auto-updated Jun 20, 2026
Patch available. Sources: cisa.
cisa Patch Available

Siemens SIMATIC UltraVNC HMI WinCC Products | CISA

https://us-cert.cisa.gov/ics/advisories/icsa-21-131-11

Vendor Advisories for CVE-2021-27384(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 11× in last 7d / 47× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-22 14:06 UTCEPSS rescore
  2. 2026-07-22 14:06 UTCEPSS rescore
  3. 2026-07-21 15:22 UTCEPSS rescore
  4. 2026-07-21 15:22 UTCEPSS rescore
  5. 2026-07-20 17:05 UTCEPSS rescore
  6. 2026-07-19 14:28 UTCEPSS rescore
  7. 2026-07-19 02:27 UTCEPSS rescore
  8. 2026-07-19 02:27 UTCEPSS rescore
  9. 2026-07-18 10:02 UTCEPSS rescore
  10. 2026-07-18 10:02 UTCEPSS rescore
  11. 2026-07-16 17:00 UTCEPSS rescore
  12. 2026-07-15 16:55 UTCEPSS rescore
  13. 2026-07-15 16:55 UTCEPSS rescore
  14. 2026-07-15 01:58 UTCEPSS rescore
  15. 2026-07-13 22:27 UTCEPSS rescore
  16. 2026-07-13 22:27 UTCEPSS rescore
  17. 2026-07-13 06:10 UTCEPSS rescore
  18. 2026-07-12 05:44 UTCEPSS rescore
  19. 2026-07-12 05:44 UTCEPSS rescore
  20. 2026-07-11 08:25 UTCEPSS rescore
  21. 2026-07-11 08:25 UTCEPSS rescore
  22. 2026-07-09 19:07 UTCEPSS rescore
  23. 2026-07-08 15:12 UTCEPSS rescore
  24. 2026-07-07 13:43 UTCEPSS rescore
  25. 2026-07-06 16:25 UTCEPSS rescore
Show 72 more
  1. 2026-07-06 16:25 UTCEPSS rescore
  2. 2026-07-06 02:21 UTCEPSS rescore
  3. 2026-07-06 02:21 UTCEPSS rescore
  4. 2026-07-05 02:28 UTCEPSS rescore
  5. 2026-07-04 06:29 UTCEPSS rescore
  6. 2026-07-04 06:29 UTCEPSS rescore
  7. 2026-07-02 16:57 UTCEPSS rescore
  8. 2026-07-01 15:03 UTCEPSS rescore
  9. 2026-06-30 23:20 UTCEPSS rescore
  10. 2026-06-30 23:20 UTCEPSS rescore
  11. 2026-06-29 14:04 UTCEPSS rescore
  12. 2026-06-28 14:05 UTCEPSS rescore
  13. 2026-06-28 04:54 UTCEPSS rescore
  14. 2026-06-28 04:54 UTCEPSS rescore
  15. 2026-06-27 03:06 UTCEPSS rescore
  16. 2026-06-27 03:06 UTCEPSS rescore
  17. 2026-06-25 13:48 UTCEPSS rescore
  18. 2026-06-25 13:48 UTCEPSS rescore
  19. 2026-06-24 14:03 UTCEPSS rescore
  20. 2026-06-24 14:03 UTCEPSS rescore
  21. 2026-06-23 21:31 UTCEPSS rescore
  22. 2026-06-23 21:31 UTCEPSS rescore
  23. 2026-06-22 14:24 UTCEPSS rescore
  24. 2026-06-22 14:24 UTCEPSS rescore
  25. 2026-06-21 14:55 UTCEPSS rescore
  26. 2026-06-21 14:54 UTCEPSS rescore
  27. 2026-06-21 01:58 UTCEPSS rescore
  28. 2026-06-21 01:58 UTCEPSS rescore
  29. 2026-06-19 19:24 UTCEPSS rescore
  30. 2026-06-19 19:24 UTCEPSS rescore
  31. 2026-06-18 17:51 UTCEPSS rescore
  32. 2026-06-18 17:51 UTCEPSS rescore
  33. 2026-06-17 17:51 UTCEPSS rescore
  34. 2026-06-16 17:51 UTCEPSS rescore
  35. 2026-06-15 17:46 UTCEPSS rescore
  36. 2026-06-14 23:15 UTCEPSS rescore
  37. 2026-06-13 22:58 UTCEPSS rescore
  38. 2026-06-13 22:58 UTCEPSS rescore
  39. 2026-06-12 23:10 UTCEPSS rescore
  40. 2026-06-11 13:58 UTCEPSS rescore
  41. 2026-06-10 22:16 UTCEPSS rescore
  42. 2026-06-10 13:20 UTCEPSS rescore
  43. 2026-06-08 14:15 UTCEPSS rescore
  44. 2026-06-07 15:23 UTCEPSS rescore
  45. 2026-06-07 15:23 UTCEPSS rescore
  46. 2026-06-06 13:46 UTCEPSS rescore
  47. 2026-06-06 13:46 UTCEPSS rescore
  48. 2026-06-06 13:46 UTCEPSS rescore
  49. 2026-06-05 22:45 UTCEPSS rescore
  50. 2026-06-05 22:45 UTCEPSS rescore
  51. 2026-06-05 06:09 UTCEPSS rescore
  52. 2026-06-05 06:09 UTCEPSS rescore
  53. 2026-06-04 13:10 UTCEPSS rescore
  54. 2026-06-04 13:10 UTCEPSS rescore
  55. 2026-06-02 20:11 UTCEPSS rescore
  56. 2026-06-02 20:11 UTCEPSS rescore
  57. 2026-06-02 20:11 UTCEPSS rescore
  58. 2026-06-01 13:50 UTCEPSS rescore
  59. 2026-06-01 13:50 UTCEPSS rescore
  60. 2026-05-31 22:29 UTCEPSS rescore
  61. 2026-05-31 22:29 UTCEPSS rescore
  62. 2026-05-31 00:15 UTCEPSS rescore
  63. 2026-05-29 13:42 UTCEPSS rescore
  64. 2026-05-28 13:43 UTCEPSS rescore
  65. 2026-05-28 13:43 UTCEPSS rescore
  66. 2026-05-27 13:39 UTCEPSS rescore
  67. 2026-05-27 13:39 UTCEPSS rescore
  68. 2026-05-26 16:42 UTCEG score recompute
  69. 2026-05-26 16:42 UTCGHSA enrichment
  70. 2026-05-26 13:42 UTCEPSS rescore
  71. 2026-05-26 07:17 UTCEPSS rescore
  72. 2026-05-26 07:17 UTCEPSS rescore

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2021-27384?
CVE-2021-27384 is a critical vulnerability published on May 12, 2021. A vulnerability has been identified in SIMATIC HMI Comfort Outdoor Panels V15 7\" & 15\" (incl. SIPLUS variants) (All versions < V15.1 Update 6), SIMATIC HMI Comfort Outdoor Panels V16 7\" & 15\" (incl. SIPLUS variants) (All versions < V16 Update 4), SIMATIC HMI Comfort Panels V15 4\" - 22\" (incl.…
When was CVE-2021-27384 disclosed?
CVE-2021-27384 was first published in the National Vulnerability Database on May 12, 2021, with the most recent update on June 2, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-27384 actively exploited?
CVE-2021-27384 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 83.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2021-27384?
CVE-2021-27384 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2021-27384?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-27384, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2021-27384

Explore →

Is Your Infrastructure Affected by CVE-2021-27384?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs