FKIE_CVE-2020-15955

Vulnerability from fkie_nvd - Published: 2021-08-17 18:15 - Updated: 2026-06-17 02:57
Severity
5.9 (Medium) - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Summary
In s/qmail through 4.0.07, an active MitM can inject arbitrary plaintext commands into a STARTTLS encrypted session between an SMTP client and s/qmail. This allows e-mail messages and user credentials to be sent to the MitM attacker.
References
cve@mitre.orghttps://nostarttls.secvuln.info/Technical Description, Third Party Advisory
cve@mitre.orghttps://www.fehcom.de/sqmail/sqmail.htmlPatch, Release Notes, Vendor Advisory
af854a3a-2127-422b-91ae-364da2661108https://nostarttls.secvuln.info/Technical Description, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://www.fehcom.de/sqmail/sqmail.htmlPatch, Release Notes, Vendor Advisory
Impacted products
Vendor Product Version
fehcom s\/qmail *
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "n/a",
          "vendor": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "n/a"
            }
          ]
        }
      ],
      "source": "cve@mitre.org"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:fehcom:s\\/qmail:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "0C54C1F3-0745-4427-96E1-C67B75B15B5D",
              "versionEndIncluding": "4.0.07",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In s/qmail through 4.0.07, an active MitM can inject arbitrary plaintext commands into a STARTTLS encrypted session between an SMTP client and s/qmail. This allows e-mail messages and user credentials to be sent to the MitM attacker."
    },
    {
      "lang": "es",
      "value": "En s/qmail versiones hasta 4.0.07, un MitM activo puede inyectar comandos de texto plano arbitrario en una sesi\u00f3n cifrada STARTTLS entre un cliente SMTP y s/qmail. Esto permite enviar mensajes de correo electr\u00f3nico y credenciales de usuario al atacante MitM."
    }
  ],
  "id": "CVE-2020-15955",
  "lastModified": "2026-06-17T02:57:29.223",
  "metrics": {
    "cvssMetricV2": [
      {
        "acInsufInfo": false,
        "baseSeverity": "MEDIUM",
        "cvssData": {
          "accessComplexity": "MEDIUM",
          "accessVector": "NETWORK",
          "authentication": "NONE",
          "availabilityImpact": "NONE",
          "baseScore": 4.3,
          "confidentialityImpact": "PARTIAL",
          "integrityImpact": "NONE",
          "vectorString": "AV:N/AC:M/Au:N/C:P/I:N/A:N",
          "version": "2.0"
        },
        "exploitabilityScore": 8.6,
        "impactScore": 2.9,
        "obtainAllPrivilege": false,
        "obtainOtherPrivilege": false,
        "obtainUserPrivilege": false,
        "source": "nvd@nist.gov",
        "type": "Primary",
        "userInteractionRequired": false
      }
    ],
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 5.9,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 2.2,
        "impactScore": 3.6,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2021-08-17T18:15:06.990",
  "references": [
    {
      "source": "cve@mitre.org",
      "tags": [
        "Technical Description",
        "Third Party Advisory"
      ],
      "url": "https://nostarttls.secvuln.info/"
    },
    {
      "source": "cve@mitre.org",
      "tags": [
        "Patch",
        "Release Notes",
        "Vendor Advisory"
      ],
      "url": "https://www.fehcom.de/sqmail/sqmail.html"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Technical Description",
        "Third Party Advisory"
      ],
      "url": "https://nostarttls.secvuln.info/"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Patch",
        "Release Notes",
        "Vendor Advisory"
      ],
      "url": "https://www.fehcom.de/sqmail/sqmail.html"
    }
  ],
  "sourceIdentifier": "cve@mitre.org",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-77"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



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