KEV Entry

CVE-2021-20837

Known Exploited Vulnerability Entry External Catalog

Back to Catalog View Vulnerability
Entry Details
Confirmed Exploited

CVE-2021-20837

2025-12-10 00:00 UTC

Characteristics

98.0

Timestamps

2023-10-14

2023-10-14

2025-12-10

Scope

Affected: Six Apart (Movable Type) / Movable Type | Class: cms | Severity: Critical (CVSS 9.8) | IoT: no | In CISA KEV: no | Honeypot connections on 2025-12-10: 1

References
  • {'id': 'CVE-2021-20837', 'url': 'https://www.cve.org/CVERecord?id=CVE-2021-20837'}
  • {'id': 'shadowserver', 'url': 'https://www.shadowserver.org/what-we-do/network-reporting/honeypot-exploited-vulnerabilities-report/'}

415cf380-bed2-47ba-8f7b-2c08be118fd6

c8fb6bf1-f81f-4cb8-95b1-eadbb3b54ee8

2026-06-30 09:22 UTC

2026-06-30 10:21 UTC

Evidence
1
Type Source Signal Confidence Details GCVE Metadata
honeypot shadowserver in_the_wild_attempts 0.70
View details 
{
  "1d": "1",
  "30d_avg": 2,
  "7d_avg": 6,
  "90d_avg": 2,
  "cisa_kev": "no",
  "class": "cms",
  "connections": 1,
  "feed": "Shadowserver Foundation honeypot/exploited-vulnerabilities",
  "iot": "no",
  "observation_date": "2025-12-10",
  "product": "Movable Type",
  "type": "http-scan",
  "vendor": "Six Apart (Movable Type)",
  "vulnerability_class": "CVSS",
  "vulnerability_score": 9.8,
  "vulnerability_severity": "Critical"
}
 -
Export Options
JSON Object JSON API View Full Catalog