CVE-2021-20035

CRITICALNVD 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
9.0EG
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS PROB: 4%CVSS: 6.5Exploit: cisa kev · ssvc activeExposed: 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 PROB
4%
EPSS %ILE
90%
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 55× in last 7d / 234× 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 765 total refreshes for this CVE.

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

Related CVEs(same CWE)

Frequently asked(6)

What is CVE-2021-20035?
CVE-2021-20035 is a critical 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.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2021-20035

Explore →

Is Your Infrastructure Affected by CVE-2021-20035?

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

Start Free Scan →Browse All CVEs