KEV Entry

CVE-2023-28771

Known Exploited Vulnerability Entry External Catalog

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Entry Details
Confirmed Exploited

CVE-2023-28771

2023-05-31 00:00 UTC

Timestamps

2023-05-31

2023-05-31

Scope

KEVIntel entry: Improper error message handling in Zyxel ZyWALL/USG series firmware versions 4.60 through 4.73, VPN series firmware versions 4.60 through 5.35, USG... | Affected: Zyxel / ZyWALL/USG series firmware, VPN series firmware, USG FLEX series firmware, ATP series firmware | CVSS: 9.8 (CRITICAL) | EPSS: 0.99284 | Used in malware: unknown | Not yet in CISA KEV: False

References
  • {'id': 'CVE-2023-28771', 'url': 'https://www.cve.org/CVERecord?id=CVE-2023-28771'}
  • {'id': 'kevintel', 'url': 'https://kevintel.com/vuln/CVE-2023-28771'}

4ed23fe9-93c2-49ac-b9f1-49f6b30efcf5

caeb2787-0d58-4236-9039-7c86c3e566f3

2026-06-23 11:14 UTC

2026-06-23 11:14 UTC

Evidence
1
Type Source Signal Confidence Details GCVE Metadata
public_report kevintel successful_exploitation 0.70
View details 
{
  "added_date": "2023-05-31T00:00:00.000Z",
  "ahead_of_cisa_kev": null,
  "cvss_score": 9.8,
  "cvss_severity": "CRITICAL",
  "epss_percentile": 0.99931,
  "epss_score": 0.99284,
  "feed": "KEVIntel (kevintel.com)",
  "not_yet_in_cisa_kev": false,
  "product": "ZyWALL/USG series firmware, VPN series firmware, USG FLEX series firmware, ATP series firmware",
  "title": "Improper error message handling in Zyxel ZyWALL/USG series firmware versions 4.60 through 4.73, VPN series firmware versions 4.60 through 5.35, USG...",
  "used_in_malware": "unknown",
  "vendor": "Zyxel"
}
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