CVE-2017-2624

Estado: ModificadaAlta (7)—

It was found that xorg-x11-server before 1.19.0 including uses memcmp() to check the received MIT cookie against a series of valid cookies. If the cookie is correct, it is allowed to attach to the Xorg session. Since most memcmp() implementations return after an invalid byte is seen, this causes a time difference between a valid and invalid byte, which could allow an efficient brute force attack.

CVSS

Versión: 3.0
Vector: CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Puntuación base: 7

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.67%
Percentil entre todas las CVEs puntuadas: 50
Fecha de la puntuación: 7/10/2026

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 (2)

Debian — Debian Linux X.org — X Server

CWE

CWE-385
CWE-200

Referencias

JSON original (NVD)

Mostrar

{
  "id": "CVE-2017-2624",
  "cveTags": [],
  "metrics": {
    "cvssMetricV2": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "version": "2.0",
          "baseScore": 1.9,
          "accessVector": "LOCAL",
          "vectorString": "AV:L/AC:M/Au:N/C:P/I:N/A:N",
          "authentication": "NONE",
          "integrityImpact": "NONE",
          "accessComplexity": "MEDIUM",
          "availabilityImpact": "NONE",
          "confidentialityImpact": "PARTIAL"
        },
        "acInsufInfo": false,
        "impactScore": 2.9,
        "baseSeverity": "LOW",
        "obtainAllPrivilege": false,
        "exploitabilityScore": 3.4,
        "obtainUserPrivilege": false,
        "obtainOtherPrivilege": false,
        "userInteractionRequired": false
      }
    ],
    "cvssMetricV30": [
      {
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        "cvssData": {
          "scope": "CHANGED",
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          "attackVector": "LOCAL",
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          "vectorString": "CVSS:3.0/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "HIGH",
          "availabilityImpact": "NONE",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 4,
        "exploitabilityScore": 1.4
      },
      {
        "type": "Primary",
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        "cvssData": {
          "scope": "UNCHANGED",
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          "attackVector": "LOCAL",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "HIGH",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "HIGH"
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        "exploitabilityScore": 1
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  "affected": [
    {
      "source": "secalert@redhat.com",
      "affectedData": [
        {
          "vendor": "Xorg",
          "product": "xorg-x11-server",
          "versions": [
            {
              "status": "affected",
              "version": "1.19.0"
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  ],
  "published": "2018-07-27T18:29:00.827",
  "references": [
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    {
      "url": "https://www.x41-dsec.de/lab/advisories/x41-2017-001-xorg/",
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  "vulnStatus": "Modified",
  "weaknesses": [
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      "source": "secalert@redhat.com",
      "description": [
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          "value": "CWE-385"
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      "description": [
        {
          "lang": "en",
          "value": "CWE-200"
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  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "It was found that xorg-x11-server before 1.19.0 including uses memcmp() to check the received MIT cookie against a series of valid cookies. If the cookie is correct, it is allowed to attach to the Xorg session. Since most memcmp() implementations return after an invalid byte is seen, this causes a time difference between a valid and invalid byte, which could allow an efficient brute force attack."
    },
    {
      "lang": "es",
      "value": "Se ha encontrado que xorg-x11-server en versiones anteriores a la 1.19.0 que uttilizan memcmp() para comprobar la cookie MIT recibida contra una serie de cookies válidas. Si la cookie es correcta, se puede adjuntar a la sesión de Xorg. Dado que la mayoría de las implementaciones de memcmp() retornan después de que se identifique un byte no válido, esto provoca una diferencia de tiempo entre un byte válido y otro no válido, lo que podría permitir un ataque de fuerza bruta eficiente."
    }
  ],
  "lastModified": "2026-06-17T01:16:32.113",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
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              "criteria": "cpe:2.3:a:x.org:x_server:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "B1C84A19-1449-4B04-9A47-D3C1A1152ED3",
              "versionEndIncluding": "1.19.4"
            }
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          "operator": "OR"
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          "operator": "OR"
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  "sourceIdentifier": "secalert@redhat.com"
}