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CVE-2021-34557

Estado: ModificadaMedia (4.6)—

XScreenSaver 5.45 can be bypassed if the machine has more than ten disconnectable video outputs. A buffer overflow in update_screen_layout() allows an attacker to bypass the standard screen lock authentication mechanism by crashing XScreenSaver. The attacker must physically disconnect many video outputs.

CVSS

Probabilidad de explotación (EPSS)

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)

Fedoraproject — FedoraXscreensaver Project — Xscreensaver

CWE

Referencias

JSON original (NVD)

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  "id": "CVE-2021-34557",
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  "metrics": {
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          "accessVector": "LOCAL",
          "vectorString": "AV:L/AC:L/Au:N/C:N/I:N/A:P",
          "authentication": "NONE",
          "integrityImpact": "NONE",
          "accessComplexity": "LOW",
          "availabilityImpact": "PARTIAL",
          "confidentialityImpact": "NONE"
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        "acInsufInfo": false,
        "impactScore": 2.9,
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        "obtainAllPrivilege": false,
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          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "integrityImpact": "NONE",
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  "affected": [
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  "published": "2021-06-10T16:15:08.227",
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  "weaknesses": [
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      "description": [
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          "value": "CWE-120"
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      "lang": "en",
      "value": "XScreenSaver 5.45 can be bypassed if the machine has more than ten disconnectable video outputs. A buffer overflow in update_screen_layout() allows an attacker to bypass the standard screen lock authentication mechanism by crashing XScreenSaver. The attacker must physically disconnect many video outputs."
    },
    {
      "lang": "es",
      "value": "XScreenSaver versión 5.45 puede ser omitido si la máquina tiene más de diez salidas de vídeo desconectables. Un desbordamiento de búfer en la función update_screen_layout() permite a un atacante omitir el mecanismo de autenticación de bloqueo de pantalla estándar, al bloquear a XScreenSaver. El atacante debe desconectar físicamente muchas salidas de vídeo"
    }
  ],
  "lastModified": "2026-06-17T03:56:07.123",
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}