CVE-2026-48693

{
  "id": "CVE-2026-48693",
  "cveTags": [],
  "metrics": {
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      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-48693",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-05-26T20:33:34.242754Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 5.5,
          "attackVector": "LOCAL",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 3.6,
        "exploitabilityScore": 1.8
      },
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        "type": "Secondary",
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
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          "version": "3.1",
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          "attackVector": "LOCAL",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 3.6,
        "exploitabilityScore": 1.8
      }
    ]
  },
  "affected": [
    {
      "source": "cve@mitre.org",
      "affectedData": [
        {
          "vendor": "n/a",
          "product": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "n/a"
            }
          ]
        }
      ]
    }
  ],
  "published": "2026-05-26T17:16:53.807",
  "references": [
    {
      "url": "https://github.com/pavel-odintsov/fastnetmon",
      "tags": [
        "Product"
      ],
      "source": "cve@mitre.org"
    },
    {
      "url": "https://github.com/pavel-odintsov/fastnetmon/blob/master/src/fastnetmon.cpp",
      "tags": [
        "Product"
      ],
      "source": "cve@mitre.org"
    },
    {
      "url": "https://github.com/pavel-odintsov/fastnetmon/blob/master/src/fastnetmon_logic.cpp",
      "tags": [
        "Product"
      ],
      "source": "cve@mitre.org"
    },
    {
      "url": "https://lorikeetsecurity.com/blog/fastnetmon-cve-2026-48693-symlink-tmp",
      "tags": [
        "Third Party Advisory"
      ],
      "source": "cve@mitre.org"
    }
  ],
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "description": [
        {
          "lang": "en",
          "value": "CWE-59"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "FastNetMon Community Edition through 1.2.9 is vulnerable to a local symlink attack via predictable file paths in /tmp. The statistics file path defaults to '/tmp/fastnetmon.dat' (src/fastnetmon.cpp line 159). The print_screen_contents_into_file() function (src/fastnetmon_logic.cpp line 2186) opens this path with std::ios::trunc without checking for symlinks or using O_NOFOLLOW. Additionally, the chmod() call on line 2190 always operates on cli_stats_file_path regardless of which file_path parameter was passed (a bug that applies wrong permissions), and the umask is set to 0 during daemonization (src/fastnetmon.cpp line 1821), making all created files world-writable. A local attacker can exploit this to overwrite arbitrary files as the FastNetMon process user (typically root)."
    },
    {
      "lang": "es",
      "value": "FastNetMon Community Edition hasta la versión 1.2.9 es vulnerable a un ataque de symlink local a través de rutas de archivo predecibles en /tmp. La ruta del archivo de estadísticas por defecto es '/tmp/fastnetmon.dat' (src/fastnetmon.cpp línea 159). La función print_screen_contents_into_file() (src/fastnetmon_logic.cpp línea 2186) abre esta ruta con std::ios::trunc sin verificar symlinks o usar O_NOFOLLOW. Además, la llamada a chmod() en la línea 2190 siempre opera sobre cli_stats_file_path independientemente del parámetro file_path que se haya pasado (un error que aplica permisos incorrectos), y el umask se establece en 0 durante la demonización (src/fastnetmon.cpp línea 1821), haciendo que todos los archivos creados sean de escritura global. Un atacante local puede explotar esto para sobrescribir archivos arbitrarios como el usuario del proceso de FastNetMon (típicamente root)."
    }
  ],
  "lastModified": "2026-07-24T11:10:00.170",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:pavel-odintsov:fastnetmon:*:*:*:*:community:*:*:*",
              "vulnerable": true,
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              "versionEndIncluding": "1.2.9"
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  "sourceIdentifier": "cve@mitre.org"
}