{"id":37225,"date":"2019-10-31T22:16:26","date_gmt":"2019-10-31T19:16:26","guid":{"rendered":"https:\/\/prohoster.info\/blog\/ataka-knob-pozvolyayushhaya-perehvatit-zashifrovannyj-trafik-bluetooth\/"},"modified":"2019-10-31T22:16:26","modified_gmt":"2019-10-31T19:16:26","slug":"ataka-knob-pozvolyayushhaya-perehvatit-zashifrovannyj-trafik-bluetooth","status":"publish","type":"post","link":"https:\/\/prohoster.info\/es\/blog\/news\/ataka-knob-pozvolyayushhaya-perehvatit-zashifrovannyj-trafik-bluetooth","title":{"rendered":"Ataque KNOB, que permite interceptar tr\u00e1fico encriptado de Bluetooth","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"<p><noindex><a rel=\"nofollow\" href=\"https:\/\/francozappa.github.io\/post\/knob-announce\/\">Revelados<\/a><\/noindex> <noindex><a rel=\"nofollow\" href=\"https:\/\/www.usenix.org\/system\/files\/sec19-antonioli.pdf\">detalles<\/a><\/noindex> sobre el ataque <noindex><a rel=\"nofollow\" href=\"https:\/\/knobattack.com\/\">KNOB<\/a><\/noindex> (Key Negotiation Of Bluetooth), que permite interceptar y sustituir informaci\u00f3n en el tr\u00e1fico cifrado de Bluetooth. Al poder bloquear la transmisi\u00f3n directa de paquetes durante la negociaci\u00f3n de la conexi\u00f3n entre dispositivos Bluetooth, un atacante puede forzar el uso de claves que contienen solo 1 byte de entrop\u00eda para la sesi\u00f3n, lo que permite aplicar un m\u00e9todo de fuerza bruta para determinar la clave de cifrado. <\/p>\n<p>El problema es causado por fallos (CVE-2019-9506) en la especificaci\u00f3n Bluetooth BR\/EDR Core 5.1 y versiones anteriores, que permiten el uso de claves de cifrado demasiado cortas y no impiden la intervenci\u00f3n de un atacante durante la etapa de negociaci\u00f3n de la conexi\u00f3n para retroceder a estas claves poco confiables (la sustituci\u00f3n de paquetes es posible por un atacante no autenticado). El ataque puede llevarse a cabo en el momento de la negociaci\u00f3n de la conexi\u00f3n de dispositivos (sesiones ya establecidas no pueden ser atacadas) y es eficaz solo para conexiones en los modos BR\/EDR (Bluetooth Tasa B\u00e1sica\/Tasa de Datos Mejorada), si ambos dispositivos son susceptibles a la vulnerabilidad. En el caso de un emparejamiento exitoso de la clave, el atacante puede descifrar datos transmitidos y, sin que la v\u00edctima se d\u00e9 cuenta, realizar una sustituci\u00f3n en el tr\u00e1fico de cualquier texto cifrado.<\/p>\n<p>Al establecer una conexi\u00f3n entre dos controladores Bluetooth A y B, el controlador A, despu\u00e9s de la autenticaci\u00f3n por clave de enlace (link key), puede ofrecer utilizar para la clave de cifrado (encryption key) 16 bytes de entrop\u00eda, y el controlador B puede aceptar este valor o indicar un valor menor si no tiene la capacidad de formar una clave del tama\u00f1o propuesto. En respuesta, el controlador A puede aceptar la oferta de respuesta y activar el canal de comunicaci\u00f3n cifrado. En esta etapa de negociaci\u00f3n, no se aplica cifrado, por lo que un atacante tiene la oportunidad de interferir en el intercambio de datos entre los controladores y sustituir el paquete con el tama\u00f1o de entrop\u00eda propuesto. Dado que el tama\u00f1o aceptable de la clave var\u00eda de 1 a 16 bytes, el segundo controlador aceptar\u00e1 este valor y enviar\u00e1 su confirmaci\u00f3n con un tama\u00f1o equivalente.<\/p>\n<p><center><noindex><a rel=\"nofollow\" href=\"https:\/\/www.usenix.org\/system\/files\/sec19-antonioli.pdf\"><img decoding=\"async\" alt=\"Ataque KNOB, que permite interceptar tr\u00e1fico encriptado de Bluetooth\" src=\"\/wp-content\/uploads\/2019\/08\/00852a72cea4b661260af415244a748b.png\" style=\"display:block;margin: 0 auto;\" \/><\/a><\/noindex><\/center><\/p>\n<p>Para reproducir la vulnerabilidad en condiciones de laboratorio (la actividad del atacante fue simulada en uno de los dispositivos) se ha propuesto<br \/>\n<noindex><a rel=\"nofollow\" href=\"https:\/\/github.com\/francozappa\/knob\/tree\/master\/poc-internalblue\">un prototipo de herramienta<\/a><\/noindex> para llevar a cabo un ataque.<br \/>\nPara un ataque real, el atacante debe estar en el rango de recepci\u00f3n de los dispositivos de las v\u00edctimas y tener la capacidad de bloquear brevemente la se\u00f1al de cada dispositivo, lo que se sugiere lograr mediante la manipulaci\u00f3n de la se\u00f1al o el apagado reactivo. <\/p>\n<p>La organizaci\u00f3n Bluetooth SIG, responsable del desarrollo de los est\u00e1ndares Bluetooth, <noindex><a rel=\"nofollow\" href=\"https:\/\/www.bluetooth.com\/security\/statement-key-negotiation-of-bluetooth\/\">ha publicado<\/a><\/noindex>  ajust\u00f3 la especificaci\u00f3n con el n\u00famero 11838, en la que se proponen medidas para que los fabricantes bloqueen la vulnerabilidad (el tama\u00f1o m\u00ednimo de la clave de cifrado se ha incrementado de 1 a 7). El problema <noindex><a rel=\"nofollow\" href=\"https:\/\/www.kb.cert.org\/vuls\/id\/918987\/\">se manifiesta<\/a><\/noindex> en  <noindex><a rel=\"nofollow\" href=\"https:\/\/www.icasi.org\/br-edr-encryption-key-bluetooth-vulnerability\/\">todas<\/a><\/noindex> los pilas Bluetooth y los firmware de chips Bluetooth que cumplen con el est\u00e1ndar, incluidos productos <noindex><a rel=\"nofollow\" href=\"https:\/\/software.intel.com\/security-software-guidance\/insights\/more-information-exploiting-low-entropy-encryption-key-negotiation-bluetooth-bredr\">Intel<\/a><\/noindex>, Broadcom, <noindex><a rel=\"nofollow\" href=\"https:\/\/support.lenovo.com\/us\/en\/product_security\/LEN-27173\">Lenovo<\/a><\/noindex>, <noindex><a rel=\"nofollow\" href=\"https:\/\/support.apple.com\/kb\/HT201222\">Apple<\/a><\/noindex>, <noindex><a rel=\"nofollow\" href=\"https:\/\/portal.msrc.microsoft.com\/en-US\/security-guidance\/advisory\/CVE-2019-9506\">Microsoft<\/a><\/noindex>, Qualcomm, Linux, <noindex><a rel=\"nofollow\" href=\"https:\/\/source.android.com\/security\/bulletin\/2019-08-01\">Android<\/a><\/noindex>, <noindex><a rel=\"nofollow\" href=\"http:\/\/support.blackberry.com\/kb\/articleDetail?articleNumber=000057251\">Blackberry<\/a><\/noindex> y <noindex><a rel=\"nofollow\" href=\"https:\/\/tools.cisco.com\/security\/center\/content\/CiscoSecurityAdvisory\/cisco-sa-20190813-bluetooth\">Cisco<\/a><\/noindex> (de 14 chips probados, todos resultaron vulnerables). En la pila Bluetooth del n\u00facleo de Linux  <noindex><a rel=\"nofollow\" href=\"https:\/\/git.kernel.org\/pub\/scm\/linux\/kernel\/git\/bluetooth\/bluetooth.git\/commit\/?id=58a96fc35375ab87db7c5b69336f5befde1b548f\">se ha introducido<\/a><\/noindex> una correcci\u00f3n que permite cambiar el tama\u00f1o m\u00ednimo de la clave de cifrado. <\/p>\n<p><noindex><a rel=\"nofollow\" name=\"link\"><\/a><\/noindex><\/p>\n<p>Fuente: <a \ncontent=\"nofollow\" rel=\"nofollow\" href=\"https:\/\/www.opennet.ru\/opennews\/art.shtml?num=51303\">opennet.ru<\/a><\/p>","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":"<p>\u0420\u0430\u0441\u043a\u0440\u044b\u0442\u044b \u0441\u0432\u0435\u0434\u0435\u043d\u0438\u044f \u043e\u0431 \u0430\u0442\u0430\u043a\u0435 KNOB (Key Negotiation Of Bluetooth), \u043f\u043e\u0437\u0432\u043e\u043b\u044f\u044e\u0449\u0435\u0439 \u043e\u0440\u0433\u0430\u043d\u0438\u0437\u043e\u0432\u0430\u0442\u044c \u043f\u0435\u0440\u0435\u0445\u0432\u0430\u0442 \u0438 \u043f\u043e\u0434\u0441\u0442\u0430\u043d\u043e\u0432\u043a\u0443 \u0438\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u0438 \u0432 \u0448\u0438\u0444\u0440\u043e\u0432\u0430\u043d\u043d\u043e\u043c Bluetooth-\u0442\u0440\u0430\u0444\u0438\u043a\u0435. \u0418\u043c\u0435\u044f \u0432\u043e\u0437\u043c\u043e\u0436\u043d\u043e\u0441\u0442\u044c \u0431\u043b\u043e\u043a\u0438\u0440\u043e\u0432\u0430\u0442\u044c \u043f\u0440\u044f\u043c\u0443\u044e \u043f\u0435\u0440\u0435\u0434\u0430\u0447\u0443 \u043f\u0430\u043a\u0435\u0442\u043e\u0432 \u0432 \u043f\u0440\u043e\u0446\u0435\u0441\u0441\u0435 \u0441\u043e\u0433\u043b\u0430\u0441\u043e\u0432\u0430\u043d\u0438\u044f \u0441\u043e\u0435\u0434\u0438\u043d\u0435\u043d\u0438\u044f Bluetooth-\u0443\u0441\u0442\u0440\u043e\u0439\u0441\u0442\u0432, \u0430\u0442\u0430\u043a\u0443\u044e\u0449\u0438\u0439 \u043c\u043e\u0436\u0435\u0442 \u0434\u043e\u0431\u0438\u0442\u044c\u0441\u044f \u0437\u0430\u0434\u0435\u0439\u0441\u0442\u0432\u043e\u0432\u0430\u043d\u0438\u044f \u0434\u043b\u044f \u0441\u0435\u0430\u043d\u0441\u0430 \u043a\u043b\u044e\u0447\u0435\u0439, \u0441\u043e\u0434\u0435\u0440\u0436\u0430\u0449\u0438\u0445 \u0432\u0441\u0435\u0433\u043e 1 \u0431\u0430\u0439\u0442 \u044d\u043d\u0442\u0440\u043e\u043f\u0438\u0438, \u0447\u0442\u043e \u043f\u043e\u0437\u0432\u043e\u043b\u044f\u0435\u0442 \u043f\u0440\u0438\u043c\u0435\u043d\u0438\u0442\u044c \u043c\u0435\u0442\u043e\u0434 \u043f\u0440\u044f\u043c\u043e\u0433\u043e \u043f\u0435\u0440\u0435\u0431\u043e\u0440\u0430 (brute-force) \u0434\u043b\u044f \u043e\u043f\u0440\u0435\u0434\u0435\u043b\u0435\u043d\u0438\u044f \u043a\u043b\u044e\u0447\u0430 \u0448\u0438\u0444\u0440\u043e\u0432\u0430\u043d\u0438\u044f. \u041f\u0440\u043e\u0431\u043b\u0435\u043c\u0430 \u0432\u044b\u0437\u0432\u0430\u043d\u0430 \u043d\u0435\u0434\u043e\u0440\u0430\u0431\u043e\u0442\u043a\u0430\u043c\u0438 [&hellip;]<\/p>\n","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"author":1,"featured_media":27914,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[702],"tags":[],"class_list":["post-37225","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news"],"aioseo_notices":[],"aioseo_head":"\n\t\t<!-- All in One SEO 5.0.2 - aioseo.com -->\n\t<meta name=\"description\" content=\"\u0420\u0430\u0441\u043a\u0440\u044b\u0442\u044b\" \/>\n\t<meta name=\"robots\" content=\"max-image-preview:large\" \/>\n\t<meta name=\"author\" content=\"Yuri Gagarin\"\/>\n\t<link rel=\"canonical\" href=\"https:\/\/prohoster.info\/es\/blog\/news\/ataka-knob-pozvolyayushhaya-perehvatit-zashifrovannyj-trafik-bluetooth\" \/>\n\t<meta name=\"generator\" content=\"All in One SEO (AIOSEO) 5.0.2\" \/>\n\t\t<meta property=\"og:locale\" content=\"es_ES\" \/>\n\t\t<meta 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