CVE-2021-20035

MEDIUMNVD 6.59.0▲
EchelonGraph scoreHIGH confidence

Score elevated to 9.0 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2025-04-16), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 6.5 retained for reference. Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: cisa_kev, epss, ghsa, nvd
Trending — 4 sources updated this weekExploited in the wild
6.5
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS: 4%CVSS: 6.5Exploit: NoneExposed: 0

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

Improper neutralization of special elements in the SMA100 management interface allows a remote authenticated attacker to inject arbitrary commands as a 'nobody' user which potentially leads to DoS.

CVSS v3
6.5
EG Score
9.0(high)
EG Risk
81(Attend)
EG Risk 81/100SSVC: Attend

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity90% × 45%
Exploitation100% × 40%
Automatability0% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS
89.9%
KEV
⚠ Exploited

Published

September 27, 2021

Last Modified

October 31, 2025

Advisory Details (2)

Auto-updated Jun 12, 2026
⚠️ Active exploitation confirmed. Patch available. Sources: cisa.
cisa Patch Available🔴 Active Exploitation

Known Exploited Vulnerabilities Catalog | CISA

Known Exploited Vulnerabilities Catalog | CISA. Listed in CISA Known Exploited Vulnerabilities catalog.

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-20035
generic

Security Advisory

https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0022

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 47× in last 7d / 216× 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.

Showing the most recent 100 of 414 total refreshes for this CVE.

  1. 2026-07-24 14:15 UTCEPSS rescore
  2. 2026-07-23 14:15 UTCEPSS rescore
  3. 2026-07-23 01:56 UTCEG score recompute
  4. 2026-07-22 21:58 UTCEG score recompute
  5. 2026-07-22 21:57 UTCGHSA enrichment
  6. 2026-07-22 19:40 UTCCISA KEV update
  7. 2026-07-22 17:34 UTCEG score recompute
  8. 2026-07-22 17:34 UTCGHSA enrichment
  9. 2026-07-22 14:05 UTCEPSS rescore
  10. 2026-07-22 13:10 UTCGHSA enrichment
  11. 2026-07-22 08:47 UTCGHSA enrichment
  12. 2026-07-22 04:22 UTCGHSA enrichment
  13. 2026-07-21 23:58 UTCGHSA enrichment
  14. 2026-07-21 17:17 UTCEG score recompute
  15. 2026-07-21 17:17 UTCGHSA enrichment
  16. 2026-07-21 15:22 UTCEPSS rescore
  17. 2026-07-21 15:22 UTCEPSS rescore
  18. 2026-07-21 14:37 UTCCISA KEV update
  19. 2026-07-21 12:54 UTCGHSA enrichment
  20. 2026-07-21 08:24 UTCGHSA enrichment
  21. 2026-07-21 04:01 UTCGHSA enrichment
  22. 2026-07-20 23:37 UTCGHSA enrichment
  23. 2026-07-20 19:14 UTCEG score recompute
  24. 2026-07-20 19:13 UTCGHSA enrichment
  25. 2026-07-20 17:04 UTCEPSS rescore
Show 75 more
  1. 2026-07-20 14:49 UTCGHSA enrichment
  2. 2026-07-20 10:14 UTCGHSA enrichment
  3. 2026-07-20 05:51 UTCGHSA enrichment
  4. 2026-07-20 01:28 UTCGHSA enrichment
  5. 2026-07-19 21:04 UTCGHSA enrichment
  6. 2026-07-19 16:40 UTCEG score recompute
  7. 2026-07-19 16:40 UTCGHSA enrichment
  8. 2026-07-19 14:28 UTCEPSS rescore
  9. 2026-07-19 12:16 UTCGHSA enrichment
  10. 2026-07-19 07:53 UTCGHSA enrichment
  11. 2026-07-19 03:30 UTCEG score recompute
  12. 2026-07-19 03:30 UTCGHSA enrichment
  13. 2026-07-19 02:26 UTCEPSS rescore
  14. 2026-07-18 23:06 UTCGHSA enrichment
  15. 2026-07-18 18:43 UTCGHSA enrichment
  16. 2026-07-18 14:20 UTCEG score recompute
  17. 2026-07-18 14:20 UTCGHSA enrichment
  18. 2026-07-18 10:02 UTCEPSS rescore
  19. 2026-07-18 09:57 UTCGHSA enrichment
  20. 2026-07-18 05:33 UTCGHSA enrichment
  21. 2026-07-18 01:09 UTCGHSA enrichment
  22. 2026-07-17 20:46 UTCGHSA enrichment
  23. 2026-07-17 16:23 UTCGHSA enrichment
  24. 2026-07-17 11:59 UTCGHSA enrichment
  25. 2026-07-17 07:36 UTCEG score recompute
  26. 2026-07-17 07:36 UTCGHSA enrichment
  27. 2026-07-17 03:12 UTCGHSA enrichment
  28. 2026-07-16 22:48 UTCGHSA enrichment
  29. 2026-07-16 18:24 UTCGHSA enrichment
  30. 2026-07-16 17:04 UTCCISA KEV update
  31. 2026-07-16 17:00 UTCEPSS rescore
  32. 2026-07-16 14:01 UTCGHSA enrichment
  33. 2026-07-16 09:38 UTCGHSA enrichment
  34. 2026-07-16 05:15 UTCGHSA enrichment
  35. 2026-07-16 00:52 UTCGHSA enrichment
  36. 2026-07-15 20:29 UTCGHSA enrichment
  37. 2026-07-15 16:55 UTCEPSS rescore
  38. 2026-07-15 16:55 UTCEPSS rescore
  39. 2026-07-15 16:49 UTCCISA KEV update
  40. 2026-07-15 16:05 UTCGHSA enrichment
  41. 2026-07-15 15:04 UTCCISA KEV update
  42. 2026-07-15 11:41 UTCGHSA enrichment
  43. 2026-07-15 07:18 UTCGHSA enrichment
  44. 2026-07-15 02:53 UTCGHSA enrichment
  45. 2026-07-15 01:57 UTCEPSS rescore
  46. 2026-07-14 22:30 UTCGHSA enrichment
  47. 2026-07-14 18:07 UTCGHSA enrichment
  48. 2026-07-14 18:05 UTCCISA KEV update
  49. 2026-07-14 13:42 UTCGHSA enrichment
  50. 2026-07-14 09:19 UTCGHSA enrichment
  51. 2026-07-14 04:54 UTCGHSA enrichment
  52. 2026-07-14 00:31 UTCGHSA enrichment
  53. 2026-07-13 22:27 UTCEPSS rescore
  54. 2026-07-13 22:27 UTCEPSS rescore
  55. 2026-07-13 20:08 UTCGHSA enrichment
  56. 2026-07-13 17:07 UTCCISA KEV update
  57. 2026-07-13 15:44 UTCGHSA enrichment
  58. 2026-07-13 11:21 UTCGHSA enrichment
  59. 2026-07-13 06:57 UTCGHSA enrichment
  60. 2026-07-13 02:33 UTCGHSA enrichment
  61. 2026-07-12 22:09 UTCGHSA enrichment
  62. 2026-07-12 17:45 UTCGHSA enrichment
  63. 2026-07-12 13:20 UTCGHSA enrichment
  64. 2026-07-12 08:57 UTCGHSA enrichment
  65. 2026-07-12 05:44 UTCEPSS rescore
  66. 2026-07-12 05:44 UTCEPSS rescore
  67. 2026-07-12 04:33 UTCGHSA enrichment
  68. 2026-07-12 00:10 UTCGHSA enrichment
  69. 2026-07-11 19:45 UTCGHSA enrichment
  70. 2026-07-11 15:22 UTCGHSA enrichment
  71. 2026-07-11 10:59 UTCGHSA enrichment
  72. 2026-07-11 08:25 UTCEPSS rescore
  73. 2026-07-11 06:35 UTCGHSA enrichment
  74. 2026-07-11 02:11 UTCGHSA enrichment
  75. 2026-07-10 21:48 UTCGHSA enrichment

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Frequently asked(6)

What is CVE-2021-20035?
CVE-2021-20035 is a medium vulnerability published on September 27, 2021. Improper neutralization of special elements in the SMA100 management interface allows a remote authenticated attacker to inject arbitrary commands as a 'nobody' user which potentially leads to DoS.
When was CVE-2021-20035 disclosed?
CVE-2021-20035 was first published in the National Vulnerability Database on September 27, 2021, with the most recent update on October 31, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-20035 actively exploited?
Yes. CISA added CVE-2021-20035 to the Known Exploited Vulnerabilities catalog on April 16, 2025, affecting SonicWall SMA100 Appliances. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.
What is the CVSS score of CVE-2021-20035?
CVE-2021-20035 has a CVSS v3 base score of 6.5 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0.
Which products are affected by CVE-2021-20035?
CVE-2021-20035 affects SonicWall SMA100 Appliances. The full affected-products list, including version ranges and fixed versions, is shown in the Affected Packages section of this page.
How do I remediate CVE-2021-20035?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-20035, 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.

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