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CVE-2023-27321

Status: AnalyzedHigh (7.5)—

OPC Foundation UA .NET Standard ConditionRefresh Resource Exhaustion Denial-of-Service Vulnerability. This vulnerability allows remote attackers to create a denial-of-service condition on affected installations of OPC Foundation UA .NET Standard. Authentication is not required to exploit this vulnerability.

The specific flaw exists within the handling of OPC UA ConditionRefresh requests. By sending a large number of requests, an attacker can consume all available resources on the server. An attacker can leverage this vulnerability to create a denial-of-service condition on the system. Was ZDI-CAN-20505.

CVSS

Exploitation probability (EPSS)

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

Affected technologies (1)

Opcfoundation — Ua-.netstandard

CWEs

References

Raw JSON (NVD)

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{
  "id": "CVE-2023-27321",
  "cveTags": [],
  "metrics": {
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        "ssvcData": {
          "id": "CVE-2023-27321",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2024-05-08T15:27:13.124910Z"
        }
      }
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    "cvssMetricV30": [
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        "cvssData": {
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          "version": "3.0",
          "baseScore": 7.5,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "NONE"
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  "published": "2024-05-07T23:15:15.760",
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  "vulnStatus": "Analyzed",
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      "description": [
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  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "OPC Foundation UA .NET Standard ConditionRefresh Resource Exhaustion Denial-of-Service Vulnerability. This vulnerability allows remote attackers to create a denial-of-service condition on affected installations of OPC Foundation UA .NET Standard. Authentication is not required to exploit this vulnerability.\n\nThe specific flaw exists within the handling of OPC UA ConditionRefresh requests. By sending a large number of requests, an attacker can consume all available resources on the server. An attacker can leverage this vulnerability to create a denial-of-service condition on the system. Was ZDI-CAN-20505."
    },
    {
      "lang": "es",
      "value": "Vulnerabilidad de denegación de servicio por agotamiento de recursos en OPC Foundation UA .NET Standard ConditionRefresh. Esta vulnerabilidad permite a atacantes remotos crear una condición de denegación de servicio en las instalaciones afectadas de OPC Foundation UA .NET Standard. No se requiere autenticación para aprovechar esta vulnerabilidad. La falla específica existe en el manejo de solicitudes OPC UA ConditionRefresh. Al enviar una gran cantidad de solicitudes, un atacante puede consumir todos los recursos disponibles en el servidor. Un atacante puede aprovechar esta vulnerabilidad para crear una condición de denegación de servicio en el sistema. Era ZDI-CAN-20505."
    }
  ],
  "lastModified": "2026-06-17T05:44:47.170",
  "configurations": [
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        {
          "negate": false,
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              "criteria": "cpe:2.3:a:opcfoundation:ua-.netstandard:*:*:*:*:*:*:*:*",
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