FKIE_CVE-2025-56353

Vulnerability from fkie_nvd - Published: 2026-01-20 16:16 - Updated: 2026-02-03 21:54
Severity ?
7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Summary
In tinyMQTT commit 6226ade15bd4f97be2d196352e64dd10937c1962 (2024-02-18), a memory leak occurs due to the broker's failure to validate or reject malformed UTF-8 strings in topic filters. An attacker can exploit this by sending repeated subscription requests with arbitrarily large or invalid filter payloads. Each request causes memory to be allocated for the malformed topic filter, but the broker does not free the associated memory, leading to unbounded heap growth and potential denial of service under sustained attack.
References
cve@mitre.orghttps://github.com/JustDoIt0910/tinyMQTT/issues/19Exploit, Issue Tracking, Third Party Advisory
Impacted products
Vendor Product Version
justdoit0910 tinymqtt 2024-02-18
To clipboard 

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  "descriptions": [
    {
      "lang": "en",
      "value": "In tinyMQTT commit 6226ade15bd4f97be2d196352e64dd10937c1962 (2024-02-18), a memory leak occurs due to the broker\u0027s failure to validate or reject malformed UTF-8 strings in topic filters. An attacker can exploit this by sending repeated subscription requests with arbitrarily large or invalid filter payloads. Each request causes memory to be allocated for the malformed topic filter, but the broker does not free the associated memory, leading to unbounded heap growth and potential denial of service under sustained attack."
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    {
      "lang": "es",
      "value": "En el commit 6226ade15bd4f97be2d196352e64dd10937c1962 (18-02-2024) de tinyMQTT, se produce una fuga de memoria debido a que el br\u00f3ker no valida ni rechaza cadenas UTF-8 mal formadas en los filtros de temas. Un atacante puede explotar esto enviando solicitudes de suscripci\u00f3n repetidas con cargas \u00fatiles de filtro arbitrariamente grandes o inv\u00e1lidas. Cada solicitud provoca que se asigne memoria para el filtro de tema mal formado, pero el br\u00f3ker no libera la memoria asociada, lo que lleva a un crecimiento ilimitado del heap y a una posible denegaci\u00f3n de servicio bajo un ataque sostenido."
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  "id": "CVE-2025-56353",
  "lastModified": "2026-02-03T21:54:46.370",
  "metrics": {
    "cvssMetricV31": [
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        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
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      "url": "https://github.com/JustDoIt0910/tinyMQTT/issues/19"
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  "vulnStatus": "Analyzed",
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