V j\u00e1d\u0159e Linux byla zji\u0161t\u011bna zranitelnost (CVE-2022-42896), kter\u00e1 m\u016f\u017ee potenci\u00e1ln\u011b b\u00fdt vyu\u017eita k organizaci vzd\u00e1len\u00e9ho spu\u0161t\u011bn\u00ed k\u00f3du na \u00farovni j\u00e1dra prost\u0159ednictv\u00edm zasl\u00e1n\u00ed speci\u00e1ln\u011b form\u00e1tovan\u00e9ho L2CAP paketu prost\u0159ednictv\u00edm Bluetooth. Krom\u011b toho byla odhalena dal\u0161\u00ed podobn\u00e1 probl\u00e9m (CVE-2022-42895) v zpracovateli L2CAP, kter\u00fd m\u016f\u017ee v\u00e9st k \u00faniku obsahu pam\u011bti j\u00e1dra v paketech se zpr\u00e1vami o konfiguraci. Prvn\u00ed zranitelnost se projevuje od srpna 2014 (j\u00e1dro 3.16), zat\u00edmco druh\u00e1 od \u0159\u00edjna 2011 (j\u00e1dro 3.0). Zranitelnosti byly opraveny ve vyd\u00e1n\u00edch j\u00e1dra Linux 6.1.0, 6.0.8, 4.9.333, 4.14.299, 4.19.265, 5.4.224, 5.10.154 a 5.15.78. Sledovat opravy v distribuc\u00edch lze na n\u00e1sleduj\u00edc\u00edch str\u00e1nk\u00e1ch: Debian, Ubuntu, Gentoo, RHEL, SUSE, Fedora, Arch. <\/p>\n
K v demonstraci mo\u017enosti proveden\u00ed vzd\u00e1len\u00e9ho \u00fatoku byly zve\u0159ejn\u011bny prototypy exploit\u016f funguj\u00edc\u00edch na Ubuntu 22.04. \u00dato\u010dn\u00edk mus\u00ed b\u00fdt v dosahu Bluetooth \u2014 nen\u00ed nutn\u00e9 p\u0159edchoz\u00ed sp\u00e1rov\u00e1n\u00ed, ale Bluetooth mus\u00ed b\u00fdt na po\u010d\u00edta\u010di aktivn\u00ed. K \u00fatoku sta\u010d\u00ed zn\u00e1t MAC adresu za\u0159\u00edzen\u00ed ob\u011bti, kter\u00e1 m\u016f\u017ee b\u00fdt ur\u010dena pomoc\u00ed snifferu nebo na n\u011bkter\u00fdch za\u0159\u00edzen\u00edch vypo\u010dtena na z\u00e1klad\u011b MAC adresy Wi-Fi. <\/p>\n
Prvn\u00ed zranitelnost (CVE-2022-42896) je zp\u016fsobena p\u0159\u00edstupem k ji\u017e uvoln\u011bn\u00e9 oblasti pam\u011bti (use-after-free) ve funkci l2cap_connect a l2cap_le_connect_req \u2014 po vytvo\u0159en\u00ed kan\u00e1lu prost\u0159ednictv\u00edm callbacku new_connection nebyla nastavena z\u00e1mkov\u00e1 ochrana, av\u0161ak byl nastaven \u010dasova\u010d (__set_chan_timer), kter\u00fd po uplynut\u00ed \u010dasov\u00e9ho limitu vyvolal funkci l2cap_chan_timeout a vy\u010distil kan\u00e1l bez kontroly ukon\u010den\u00ed pr\u00e1ce s kan\u00e1lem ve funkc\u00edch l2cap_le_connect*. <\/p>\n
V\u00fdchoz\u00ed \u010dasov\u00fd limit \u010din\u00ed 40 sekund a p\u0159edpokl\u00e1dalo se, \u017ee stav z\u00e1vodu p\u0159i takov\u00e9m zpo\u017ed\u011bn\u00ed nem\u016f\u017ee vzniknout, ale uk\u00e1zalo se, \u017ee kv\u016fli jin\u00e9 chyb\u011b v zpracovateli SMP lze dos\u00e1hnout okam\u017eit\u00e9ho vyvol\u00e1n\u00ed \u010dasova\u010de a dosa\u017een\u00ed stavu z\u00e1vodu. Probl\u00e9m v l2cap_le_connect_req m\u016f\u017ee v\u00e9st k \u00faniku pam\u011bti j\u00e1dra, zat\u00edmco v l2cap_connect k p\u0159eps\u00e1n\u00ed obsahu pam\u011bti a spu\u0161t\u011bn\u00ed vlastn\u00edho k\u00f3du. Prvn\u00ed variantu \u00fatoku lze prov\u00e9st p\u0159i pou\u017eit\u00ed Bluetooth LE 4.0 (od roku 2009), druhou p\u0159i pou\u017eit\u00ed Bluetooth BR\/EDR 5.2 (od roku 2020). <\/p>\n
Druh\u00e1 zranitelnost (CVE-2022-42895) je zp\u016fsobena \u00fanikem zbytkov\u00fdch dat z pam\u011bti ve funkci l2cap_parse_conf_req, co\u017e m\u016f\u017ee b\u00fdt vyu\u017eito k vzd\u00e1len\u00e9mu z\u00edsk\u00e1n\u00ed informac\u00ed o ukazatel\u00edch na struktury j\u00e1dra zasl\u00e1n\u00edm speci\u00e1ln\u011b upraven\u00fdch konfigura\u010dn\u00edch po\u017eadavk\u016f. Ve funkci l2cap_parse_conf_req byla pou\u017eita struktura l2cap_conf_efs, pro kterou nebyla provedena p\u0159edb\u011b\u017en\u00e1 inicializace p\u0159id\u011blen\u00e9 pam\u011bti a prost\u0159ednictv\u00edm manipulac\u00ed s p\u0159\u00edznakem FLAG_EFS_ENABLE bylo mo\u017en\u00e9 dos\u00e1hnout zahrnut\u00ed star\u00fdch dat ze z\u00e1sobn\u00edku do paketu. Probl\u00e9m se projevuje pouze v syst\u00e9mech, kde je j\u00e1dro sestaveno s volbou CONFIG_BT_HS (ve v\u00fdchoz\u00edm nastaven\u00ed je vypnuta, ale je aktivov\u00e1na v n\u011bkter\u00fdch distribuc\u00edch, nap\u0159\u00edklad v Ubuntu). Pro \u00fasp\u011b\u0161n\u00fd \u00fatok je tak\u00e9 vy\u017eadov\u00e1no nastaven\u00ed parametru HCI_HS_ENABLED prost\u0159ednictv\u00edm \u0159\u00edd\u00edc\u00edho rozhran\u00ed na hodnotu true (ve v\u00fdchoz\u00edm stavu se nepou\u017e\u00edv\u00e1). \u0412 \u044f\u0434\u0440\u0435 Linux \u0432\u044b\u044f\u0432\u043b\u0435\u043d\u0430 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c (CVE-2022-42896), \u043a\u043e\u0442\u043e\u0440\u0430\u044f \u043c\u043e\u0436\u0435\u0442 \u043f\u043e\u0442\u0435\u043d\u0446\u0438\u0430\u043b\u044c\u043d\u043e \u0438\u0441\u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u0442\u044c\u0441\u044f \u0434\u043b\u044f \u043e\u0440\u0433\u0430\u043d\u0438\u0437\u0430\u0446\u0438\u0438 \u0443\u0434\u0430\u043b\u0451\u043d\u043d\u043e\u0433\u043e \u0432\u044b\u043f\u043e\u043b\u043d\u0435\u043d\u0438\u044f \u043a\u043e\u0434\u0430 \u043d\u0430 \u0443\u0440\u043e\u0432\u043d\u0435 \u044f\u0434\u0440\u0430 \u0447\u0435\u0440\u0435\u0437 \u043e\u0442\u043f\u0440\u0430\u0432\u043a\u0443 \u0441\u043f\u0435\u0446\u0438\u0430\u043b\u044c\u043d\u043e \u043e\u0444\u043e\u0440\u043c\u043b\u0435\u043d\u043d\u043e\u0433\u043e L2CAP-\u043f\u0430\u043a\u0435\u0442\u0430 \u0447\u0435\u0440\u0435\u0437 Bluetooth. \u041a\u0440\u043e\u043c\u0435 \u0442\u043e\u0433\u043e, \u0432\u044b\u044f\u0432\u043b\u0435\u043d\u0430 \u0435\u0449\u0451 \u043e\u0434\u043d\u0430 \u043f\u043e\u0445\u043e\u0436\u0430\u044f \u043f\u0440\u043e\u0431\u043b\u0435\u043c\u0430 (CVE-2022-42895) \u0432 \u043e\u0431\u0440\u0430\u0431\u043e\u0442\u0447\u0438\u043a\u0435 L2CAP, \u043a\u043e\u0442\u043e\u0440\u0430\u044f \u043c\u043e\u0436\u0435\u0442 \u043f\u0440\u0438\u0432\u0435\u0441\u0442\u0438 \u043a \u0443\u0442\u0435\u0447\u043a\u0435 \u0441\u043e\u0434\u0435\u0440\u0436\u0438\u043c\u043e\u0433\u043e \u043f\u0430\u043c\u044f\u0442\u0438 \u044f\u0434\u0440\u0430 \u0432 \u043f\u0430\u043a\u0435\u0442\u0430\u0445 \u0441\u043e \u0441\u0432\u0435\u0434\u0435\u043d\u0438\u044f\u043c\u0438 \u043e \u043a\u043e\u043d\u0444\u0438\u0433\u0443\u0440\u0430\u0446\u0438\u0438. \u041f\u0435\u0440\u0432\u0430\u044f \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u043f\u0440\u043e\u044f\u0432\u043b\u044f\u0435\u0442\u0441\u044f \u0441 \u0430\u0432\u0433\u0443\u0441\u0442\u0430 […]<\/p>\n","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[702],"tags":[],"class_list":["post-106088","post","type-post","status-publish","format-standard","hentry","category-news"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\n","aioseo_head_json":{"title":"\ud83e\udd47Zranitelnosti v j\u00e1d\u0159e Linuxu, kter\u00e9 lze vzd\u00e1len\u011b zneu\u017e\u00edt p\u0159es Bluetooth | ProHoster","description":"V j\u00e1d\u0159e Linuxu byla zji\u0161t\u011bna zranitelnost (CVE-2022-42896), kter\u00e1 m\u016f\u017ee potenci\u00e1ln\u011b b\u00fdt vyu\u017eita k organizaci vzd\u00e1len\u00e9ho spu\u0161t\u011bn\u00ed k\u00f3du na \u00farovni j\u00e1dra prost\u0159ednictv\u00edm zasl\u00e1n\u00ed speci\u00e1ln\u011b upraven\u00e9ho L2CAP paketu.","canonical_url":"https:\/\/prohoster.info\/cs\/blog\/news\/uyazvimosti-v-yadre-linux-udalyonno-ekspluatiruemye-cherez-bluetooth","robots":"max-image-preview:large","keywords":"","webmasterTools":{"miscellaneous":""},"schema":null,"og:locale":"cs_CZ","og:site_name":"ProHoster | \u041a\u0443\u043f\u0438\u0442\u044c \u043d\u0430\u0434\u0435\u0436\u043d\u044b\u0439 \u0445\u043e\u0441\u0442\u0438\u043d\u0433 \u0434\u043b\u044f \u0441\u0430\u0439\u0442\u043e\u0432 \u0441 \u0437\u0430\u0449\u0438\u0442\u043e\u0439 \u043e\u0442 DDoS, VPS VDS \u0441\u0435\u0440\u0432\u0435\u0440\u044b","og:type":"article","og:title":"\ud83e\udd47\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438 \u0432 \u044f\u0434\u0440\u0435 Linux, \u0443\u0434\u0430\u043b\u0451\u043d\u043d\u043e \u044d\u043a\u0441\u043f\u043b\u0443\u0430\u0442\u0438\u0440\u0443\u0435\u043c\u044b\u0435 \u0447\u0435\u0440\u0435\u0437 Bluetooth | ProHoster","og:description":"\u0412 \u044f\u0434\u0440\u0435 Linux \u0432\u044b\u044f\u0432\u043b\u0435\u043d\u0430 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c (CVE-2022-42896), \u043a\u043e\u0442\u043e\u0440\u0430\u044f \u043c\u043e\u0436\u0435\u0442 \u043f\u043e\u0442\u0435\u043d\u0446\u0438\u0430\u043b\u044c\u043d\u043e \u0438\u0441\u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u0442\u044c\u0441\u044f \u0434\u043b\u044f \u043e\u0440\u0433\u0430\u043d\u0438\u0437\u0430\u0446\u0438\u0438 \u0443\u0434\u0430\u043b\u0451\u043d\u043d\u043e\u0433\u043e \u0432\u044b\u043f\u043e\u043b\u043d\u0435\u043d\u0438\u044f \u043a\u043e\u0434\u0430 \u043d\u0430 \u0443\u0440\u043e\u0432\u043d\u0435 \u044f\u0434\u0440\u0430 \u0447\u0435\u0440\u0435\u0437 \u043e\u0442\u043f\u0440\u0430\u0432\u043a\u0443 \u0441\u043f\u0435\u0446\u0438\u0430\u043b\u044c\u043d\u043e \u043e\u0444\u043e\u0440\u043c\u043b\u0435\u043d\u043d\u043e\u0433\u043e L2CAP-\u043f\u0430\u043a\u0435\u0442\u0430 \u0447\u0435\u0440\u0435\u0437.","og:url":"https:\/\/prohoster.info\/cs\/blog\/news\/uyazvimosti-v-yadre-linux-udalyonno-ekspluatiruemye-cherez-bluetooth","og:image":"https:\/\/prohoster.info\/wp-content\/uploads\/2021\/11\/logo-350.jpg","og:image:secure_url":"https:\/\/prohoster.info\/wp-content\/uploads\/2021\/11\/logo-350.jpg","og:image:width":350,"og:image:height":350,"article:published_time":"2022-12-15T11:06:35+00:00","article:modified_time":"2022-12-15T11:06:35+00:00","article:publisher":"https:\/\/www.facebook.com\/prohoster","article:author":"https:\/\/www.facebook.com\/prohoster"},"aioseo_meta_data":[],"gt_translate_keys":[{"key":"link","format":"url"}],"_links":{"self":[{"href":"https:\/\/prohoster.info\/cs\/wp-json\/wp\/v2\/posts\/106088","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/prohoster.info\/cs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/prohoster.info\/cs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/prohoster.info\/cs\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/prohoster.info\/cs\/wp-json\/wp\/v2\/comments?post=106088"}],"version-history":[{"count":0,"href":"https:\/\/prohoster.info\/cs\/wp-json\/wp\/v2\/posts\/106088\/revisions"}],"wp:attachment":[{"href":"https:\/\/prohoster.info\/cs\/wp-json\/wp\/v2\/media?parent=106088"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/prohoster.info\/cs\/wp-json\/wp\/v2\/categories?post=106088"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/prohoster.info\/cs\/wp-json\/wp\/v2\/tags?post=106088"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
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Zdroj: opennet.ru<\/a> <\/p>","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":"