CVE-2014-3556

Estado: ModificadaMedia (6.8)—

The STARTTLS implementation in mail/ngx_mail_smtp_handler.c in the SMTP proxy in nginx 1.5.x and 1.6.x before 1.6.1 and 1.7.x before 1.7.4 does not properly restrict I/O buffering, which allows man-in-the-middle attackers to insert commands into encrypted SMTP sessions by sending a cleartext command that is processed after TLS is in place, related to a "plaintext command injection" attack, a similar issue to CVE-2011-0411.

CVSS

Versión: 2.0
Vector: AV:N/AC:M/Au:N/C:P/I:P/A:P
Puntuación base: 6.8

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 7.83%
Percentil entre todas las CVEs puntuadas: 95
Fecha de la puntuación: 2/10/2026

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

Tecnologías afectadas (1)

F5 — Nginx

CWE

CWE-77

Referencias

JSON original (NVD)

Mostrar

{
  "id": "CVE-2014-3556",
  "cveTags": [],
  "metrics": {
    "cvssMetricV2": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "version": "2.0",
          "baseScore": 6.8,
          "accessVector": "NETWORK",
          "vectorString": "AV:N/AC:M/Au:N/C:P/I:P/A:P",
          "authentication": "NONE",
          "integrityImpact": "PARTIAL",
          "accessComplexity": "MEDIUM",
          "availabilityImpact": "PARTIAL",
          "confidentialityImpact": "PARTIAL"
        },
        "acInsufInfo": false,
        "impactScore": 6.4,
        "baseSeverity": "MEDIUM",
        "obtainAllPrivilege": false,
        "exploitabilityScore": 8.6,
        "obtainUserPrivilege": false,
        "obtainOtherPrivilege": false,
        "userInteractionRequired": false
      }
    ]
  },
  "affected": [
    {
      "source": "secalert@redhat.com",
      "affectedData": [
        {
          "vendor": "n/a",
          "product": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "n/a"
            }
          ]
        }
      ]
    }
  ],
  "published": "2014-12-29T20:59:03.943",
  "references": [
    {
      "url": "http://mailman.nginx.org/pipermail/nginx-announce/2014/000144.html",
      "tags": [
        "Patch",
        "Vendor Advisory"
      ],
      "source": "secalert@redhat.com"
    },
    {
      "url": "http://marc.info/?l=bugtraq&m=142103967620673&w=2",
      "tags": [
        "Issue Tracking",
        "Third Party Advisory"
      ],
      "source": "secalert@redhat.com"
    },
    {
      "url": "http://nginx.org/download/patch.2014.starttls.txt",
      "tags": [
        "Patch",
        "Vendor Advisory"
      ],
      "source": "secalert@redhat.com"
    },
    {
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1126891",
      "tags": [
        "Issue Tracking",
        "Third Party Advisory"
      ],
      "source": "secalert@redhat.com"
    },
    {
      "url": "http://mailman.nginx.org/pipermail/nginx-announce/2014/000144.html",
      "tags": [
        "Patch",
        "Vendor Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "http://marc.info/?l=bugtraq&m=142103967620673&w=2",
      "tags": [
        "Issue Tracking",
        "Third Party Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "http://nginx.org/download/patch.2014.starttls.txt",
      "tags": [
        "Patch",
        "Vendor Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1126891",
      "tags": [
        "Issue Tracking",
        "Third Party Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-77"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "The STARTTLS implementation in mail/ngx_mail_smtp_handler.c in the SMTP proxy in nginx 1.5.x and 1.6.x before 1.6.1 and 1.7.x before 1.7.4 does not properly restrict I/O buffering, which allows man-in-the-middle attackers to insert commands into encrypted SMTP sessions by sending a cleartext command that is processed after TLS is in place, related to a \"plaintext command injection\" attack, a similar issue to CVE-2011-0411."
    },
    {
      "lang": "es",
      "value": "La implementación STARTTLS en mail/ngx_mail_smtp_handler.c en el proxy SMTP en nginx 1.5.x y 1.6.x anterior a 1.6.1 y 1.7.x anterior a 1.7.4 no restringe adecuadamente el buffer I/O, lo que permite ataques man-in-the-middle insertar comandos en sesiones cifradas SMTP enviando el comando cleartext que se procesa después que TLS, relacionado a un ataque 'inyección de comando de texto plano', un problema similar a CVE-2011-0411"
    }
  ],
  "lastModified": "2026-06-17T00:08:28.650",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:f5:nginx:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "091FA427-14F1-480B-9AF7-BEDE2B95F554",
              "versionEndExcluding": "1.6.1",
              "versionStartIncluding": "1.5.6"
            },
            {
              "criteria": "cpe:2.3:a:f5:nginx:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "E907E772-8057-4A01-97E5-B930769CFAD2",
              "versionEndExcluding": "1.7.4",
              "versionStartIncluding": "1.7.0"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "secalert@redhat.com"
}