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CVE-2020-8517

Status: ModifiedHigh (7.5)—

An issue was discovered in Squid before 4.10. Due to incorrect input validation, the NTLM authentication credentials parser in ext_lm_group_acl may write to memory outside the credentials buffer. On systems with memory access protections, this can result in the helper process being terminated unexpectedly. This leads to the Squid process also terminating and a denial of service for all clients using the proxy.

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 (3)

Canonical — Ubuntu LinuxOpensuse — LeapSquid-cache — Squid

CWEs

References

Raw JSON (NVD)

Show
{
  "id": "CVE-2020-8517",
  "cveTags": [],
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          "accessVector": "NETWORK",
          "vectorString": "AV:N/AC:L/Au:N/C:N/I:N/A:P",
          "authentication": "NONE",
          "integrityImpact": "NONE",
          "accessComplexity": "LOW",
          "availabilityImpact": "PARTIAL",
          "confidentialityImpact": "NONE"
        },
        "acInsufInfo": false,
        "impactScore": 2.9,
        "baseSeverity": "MEDIUM",
        "obtainAllPrivilege": false,
        "exploitabilityScore": 10,
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          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "integrityImpact": "NONE",
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          "value": "CWE-787"
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      "lang": "en",
      "value": "An issue was discovered in Squid before 4.10. Due to incorrect input validation, the NTLM authentication credentials parser in ext_lm_group_acl may write to memory outside the credentials buffer. On systems with memory access protections, this can result in the helper process being terminated unexpectedly. This leads to the Squid process also terminating and a denial of service for all clients using the proxy."
    },
    {
      "lang": "es",
      "value": "Se detectó un problema en Squid versiones anteriores a 4.10. Debido a una comprobación de entrada incorrecta, el analizador de credenciales de autenticación NTLM en la función ext_lm_group_acl puede escribir en la memoria fuera del búfer de credenciales. En sistemas con protecciones de acceso a la memoria, esto puede resultar en que el proceso auxiliar termine inesperadamente. Esto conlleva a que el proceso de Squid también termine y a una denegación de servicio para todos los clientes que están usando el proxy."
    }
  ],
  "lastModified": "2026-06-17T03:26:30.343",
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}