CVE-2026-27456

{
  "id": "CVE-2026-27456",
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          "version": "2.0.3",
          "timestamp": "2026-04-06T15:38:42.794607Z"
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          "baseScore": 4.7,
          "attackVector": "LOCAL",
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          "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "HIGH",
          "availabilityImpact": "NONE",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "HIGH"
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  "affected": [
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          "vendor": "util-linux",
          "product": "util-linux",
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              "status": "affected",
              "version": "< 2.41.4"
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  "published": "2026-04-03T22:16:25.400",
  "references": [
    {
      "url": "https://github.com/util-linux/util-linux/commit/5e390467b26a3cf3fecc04e1a0d482dff3162fc4",
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      "url": "https://github.com/util-linux/util-linux/releases/tag/v2.41.4",
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    {
      "url": "https://github.com/util-linux/util-linux/security/advisories/GHSA-qq4x-vfq4-9h9g",
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      "description": [
        {
          "lang": "en",
          "value": "CWE-59"
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        {
          "lang": "en",
          "value": "CWE-269"
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        {
          "lang": "en",
          "value": "CWE-367"
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  "descriptions": [
    {
      "lang": "en",
      "value": "util-linux is a random collection of Linux utilities. Prior to version 2.41.4, a TOCTOU (Time-of-Check-Time-of-Use) vulnerability has been identified in the SUID binary /usr/bin/mount from util-linux. The mount binary, when setting up loop devices, validates the source file path with user privileges via fork() + setuid() + realpath(), but subsequently re-canonicalizes and opens it with root privileges (euid=0) without verifying that the path has not been replaced between both operations. Neither O_NOFOLLOW, nor inode comparison, nor post-open fstat() are employed. This allows a local unprivileged user to replace the source file with a symlink pointing to any root-owned file or device during the race window, causing the SUID binary to open and mount it as root. Exploitation requires an /etc/fstab entry with user,loop options whose path points to a directory where the attacker has write permission, and that /usr/bin/mount has the SUID bit set (the default configuration on virtually all Linux distributions). The impact is unauthorized read access to root-protected files and block devices, including backup images, disk volumes, and any file containing a valid filesystem. This issue has been patched in version 2.41.4."
    },
    {
      "lang": "es",
      "value": "util-linux es una colección aleatoria de utilidades de Linux. Antes de la versión 2.41.4, se ha identificado una vulnerabilidad TOCTOU (Time-of-Check-Time-of-Use) en el binario SUID /usr/bin/mount de util-linux. El binario mount, al configurar dispositivos de bucle, valida la ruta del archivo de origen con privilegios de usuario a través de fork() + setuid() + realpath(), pero posteriormente la vuelve a canonizar y la abre con privilegios de root (euid=0) sin verificar que la ruta no haya sido reemplazada entre ambas operaciones. No se emplean ni O_NOFOLLOW, ni la comparación de inodos, ni fstat() posterior a la apertura. Esto permite a un usuario local sin privilegios reemplazar el archivo de origen con un enlace simbólico que apunte a cualquier archivo o dispositivo propiedad de root durante la ventana de carrera, haciendo que el binario SUID lo abra y monte como root. La explotación requiere una entrada en /etc/fstab con las opciones user,loop cuya ruta apunte a un directorio donde el atacante tenga permiso de escritura, y que /usr/bin/mount tenga el bit SUID establecido (la configuración predeterminada en prácticamente todas las distribuciones de Linux). El impacto es el acceso de lectura no autorizado a archivos protegidos por root y dispositivos de bloque, incluyendo imágenes de respaldo, volúmenes de disco y cualquier archivo que contenga un sistema de archivos válido. Este problema ha sido parcheado en la versión 2.41.4."
    }
  ],
  "lastModified": "2026-07-24T22:10:00.140",
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