En Linux-k\u00e4rna har en s\u00e5rbarhet (CVE-2022-42896) identifierats som potentiellt kan utnyttjas f\u00f6r att utf\u00f6ra kod p\u00e5 k\u00e4rnniv\u00e5 genom att skicka ett speciellt utformat L2CAP-paket via Bluetooth. Dessutom har ett liknande problem (CVE-2022-42895) uppt\u00e4ckts i L2CAP-hanteraren, vilket kan leda till l\u00e4ckage av k\u00e4rkodens inneh\u00e5ll i paket med konfigurationsinformation. Den f\u00f6rsta s\u00e5rbarheten har funnits sedan augusti 2014 (k\u00e4rna 3.16), medan den andra funnits sedan oktober 2011 (k\u00e4rna 3.0). S\u00e5rbarheterna har \u00e5tg\u00e4rdats i versionerna av Linux-k\u00e4rnan 6.1.0, 6.0.8, 4.9.333, 4.14.299, 4.19.265, 5.4.224, 5.10.154 och 5.15.78. Du kan f\u00f6lja korrigeringarna i distributionerna p\u00e5 f\u00f6ljande sidor: Debian, Ubuntu, Gentoo, RHEL, SUSE, Fedora, Arch. <\/p>\n
F\u00f6r att demonstrera m\u00f6jligheten att genomf\u00f6ra en fj\u00e4rrattack har prototyper av exploit publicerats som fungerar i Ubuntu 22.04. F\u00f6r att utf\u00f6ra attacken m\u00e5ste angriparen befinna sig inom Bluetooth-r\u00e4ckvidd \u2014 ingen tidigare parkoppling kr\u00e4vs, men Bluetooth m\u00e5ste vara aktiverat p\u00e5 datorn. Det r\u00e4cker att k\u00e4nna till MAC-adressen f\u00f6r m\u00e5lets enhet, som kan fastst\u00e4llas genom sniffing eller ber\u00e4knas p\u00e5 vissa enheter baserat p\u00e5 MAC-adressen f\u00f6r Wi-Fi. <\/p>\n
Den f\u00f6rsta s\u00e5rbarheten (CVE-2022-42896) orsakas av ett anrop till ett redan frigivet minnesomr\u00e5de (use-after-free) i implementeringen av funktionerna l2cap_connect och l2cap_le_connect_req \u2014 efter skapandet av en kanal genom callback-anropet new_connection, st\u00e4lldes ingen l\u00e5sning in f\u00f6r den, men en timer (__set_chan_timer) konfigurerades, som, efter att tidsgr\u00e4nsen passerat, kallar funktionen l2cap_chan_timeout och rensar kanalen utan att kontrollera om arbetet med kanalen avslutats i funktionerna l2cap_le_connect*. <\/p>\n
Som standard \u00e4r tidsgr\u00e4nsen 40 sekunder och det antogs att ett race-tillst\u00e5nd inte skulle kunna uppst\u00e5 med en s\u00e5dan f\u00f6rsening, men det visade sig att p\u00e5 grund av ett annat fel i SMP-hanteraren kan en omedelbar anrop av timern uppn\u00e5s och ett race-tillst\u00e5nd n\u00e5s. Problemet i l2cap_le_connect_req kan leda till l\u00e4ckage av k\u00e4rkod och i l2cap_connect till \u00f6verskrivning av minnesinneh\u00e5ll och exekvering av egen kod. Det f\u00f6rsta attackalternativet kan utf\u00f6ras med Bluetooth LE 4.0 (sedan 2009), det andra med Bluetooth BR\/EDR 5.2 (sedan 2020). <\/p>\n
Den andra s\u00e5rbarheten (CVE-2022-42895) orsakas av l\u00e4ckage av kvarvarande data fr\u00e5n minnet i funktionen l2cap_parse_conf_req, vilket kan anv\u00e4ndas f\u00f6r att fj\u00e4rr\u00e5tkomst till information om pekare till k\u00e4rnstrukturer genom att skicka speciellt utformade konfigurationsf\u00f6rfr\u00e5gningar. I funktionen l2cap_parse_conf_req anv\u00e4ndes strukturen l2cap_conf_efs, f\u00f6r vilken ingen prelimin\u00e4r initiering av den allokerade minnet gjordes, och genom manipulation av flaggan FLAG_EFS_ENABLE kunde man f\u00e5 gamla data fr\u00e5n stacken att inkluderas i paketet. Problemet upptr\u00e4der endast i system d\u00e4r k\u00e4rnan \u00e4r kompilerad med alternativet CONFIG_BT_HS (standard \u00e4r avst\u00e4ngt, men aktiverat i vissa distributioner, exempelvis Ubuntu). F\u00f6r att en attack ska lyckas kr\u00e4vs \u00e4ven att parametern HCI_HS_ENABLED s\u00e4tts till true via det styrande gr\u00e4nssnittet (ovanligt anv\u00e4nds inte). \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\udd47S\u00e5rbarheter i Linux-k\u00e4rnan, fj\u00e4rrutnyttjade via Bluetooth | ProHoster","description":"En s\u00e5rbarhet har uppt\u00e4ckts i Linux-k\u00e4rnan (CVE-2022-42896) som potentiellt kan anv\u00e4ndas f\u00f6r att m\u00f6jligg\u00f6ra fj\u00e4rrk\u00f6rning av kod p\u00e5 k\u00e4rnniv\u00e5 genom att skicka ett speciellt utformat L2CAP-paket.","canonical_url":"https:\/\/prohoster.info\/sv\/blog\/news\/uyazvimosti-v-yadre-linux-udalyonno-ekspluatiruemye-cherez-bluetooth","robots":"max-image-preview:large","keywords":"","webmasterTools":{"miscellaneous":""},"schema":null,"og:locale":"sv_SE","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\/sv\/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\/sv\/wp-json\/wp\/v2\/posts\/106088","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/prohoster.info\/sv\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/prohoster.info\/sv\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/prohoster.info\/sv\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/prohoster.info\/sv\/wp-json\/wp\/v2\/comments?post=106088"}],"version-history":[{"count":0,"href":"https:\/\/prohoster.info\/sv\/wp-json\/wp\/v2\/posts\/106088\/revisions"}],"wp:attachment":[{"href":"https:\/\/prohoster.info\/sv\/wp-json\/wp\/v2\/media?parent=106088"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/prohoster.info\/sv\/wp-json\/wp\/v2\/categories?post=106088"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/prohoster.info\/sv\/wp-json\/wp\/v2\/tags?post=106088"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
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K\u00e4lla: opennet.ru<\/a> <\/p>","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":"