V rozhran\u00ed pro asynchronn\u00ed vstup\/v\u00fdstup io_uring, kter\u00e9 poskytuje j\u00e1dro Linux, byla nalezena zranitelnost (CVE-2024-0582), kter\u00e1 umo\u017e\u0148uje neprivilegovan\u00e9mu u\u017eivateli z\u00edskat pr\u00e1va root v syst\u00e9mu. K vyu\u017eit\u00ed zranitelnosti sta\u010d\u00ed b\u011b\u017en\u00fd m\u00edstn\u00ed p\u0159\u00edstup k syst\u00e9mu bez nutnosti manipulace s prostory jmen. V sou\u010dasnosti je ve\u0159ejn\u011b dostupn\u00fd funk\u010dn\u00ed exploit a podrobn\u011b je pops\u00e1na druh\u00e1 technika exploatace zranitelnosti. <\/p>\n
Zranitelnost je zp\u016fsobena p\u0159\u00edstupem k ji\u017e uvoln\u011bn\u00e9mu bloku pam\u011bti (use-after-free) v subsyst\u00e9mu io_uring, kter\u00e1 se vyskytuje p\u0159i registraci a uvoln\u011bn\u00ed kruhov\u00e9ho bufferu vytvo\u0159en\u00e9ho s p\u0159\u00edznakem IORING_REGISTER_PBUF_RING. V p\u0159\u00edpad\u011b pou\u017eit\u00ed operace mmap() na bufferu z\u016fst\u00e1v\u00e1 odraz v prostoru u\u017eivatele i po proveden\u00ed operace jeho uvoln\u011bn\u00ed (IORING_UNREGISTER_PBUF_RING). Vyu\u017eit\u00edm t\u00e9to vlastnosti m\u016f\u017ee \u00fato\u010dn\u00edk \u010d\u00edst a zapisovat data na str\u00e1nky pam\u011bti, kter\u00e9 byly vr\u00e1ceny syst\u00e9mem spr\u00e1vy pam\u011bti j\u00e1dra. <\/p>\n
Probl\u00e9m se projevuje od vyd\u00e1n\u00ed j\u00e1dra Linux 6.4 a byl odstran\u011bn ve verz\u00edch 6.7 a 6.6.5, jako\u017e i v bal\u00ed\u010dku j\u00e1dra 6.5.0-21, p\u0159ipraven\u00e9m pro Ubuntu 22.04 a 23.10. Je pozoruhodn\u00e9, \u017ee v hlavn\u00edm j\u00e1d\u0159e byla chyba opravena v prosinci 2023, projekt Google Zero zp\u0159\u00edstupnil signalizuj\u00edc\u00ed hl\u00e1\u0161en\u00ed o zranitelnosti 8. ledna a bal\u00ed\u010dek s opraven\u00fdm j\u00e1drem 6.5 pro Ubuntu byl sestaven a\u017e 22. \u00fanora 2024. V jin\u00fdch distribuc\u00edch je mo\u017en\u00e9 sledovat opravy a zranitelnost na str\u00e1nk\u00e1ch: Debian, Gentoo, RHEL, SUSE, Fedora, Arch. <\/p>\n
Prvn\u00ed exploit manipuluje vytv\u00e1\u0159en\u00ed velk\u00e9ho po\u010dtu str\u00e1nek pam\u011bti \u0159\u00edzen\u00fdch \u00fato\u010dn\u00edkem, aby ur\u010dil rozlo\u017een\u00ed pam\u011bti v j\u00e1d\u0159e a z\u00edskal p\u0159\u00edstup k sousedn\u00edm fyzick\u00fdm str\u00e1nk\u00e1m pam\u011bti, p\u0159i\u010dem\u017e jako maj\u00e1ky pou\u017e\u00edv\u00e1 obsah ur\u010dit\u00fdm zp\u016fsobem vypln\u011bn\u00fdch struktur s\u00ed\u0165ov\u00fdch socket\u016f. K spu\u0161t\u011bn\u00ed k\u00f3du v exploit\u011b je vyu\u017eit 'gadget' (sekvence existuj\u00edc\u00edch instrukc\u00ed v j\u00e1d\u0159e), kter\u00fd vede k proveden\u00ed funkce call_usermodehelper_exec, ur\u010den\u00e9 k spu\u0161t\u011bn\u00ed proces\u016f ve u\u017eivatelsk\u00e9m prostoru z j\u00e1dra. <\/p>\n
Druh\u00fd exploit vych\u00e1z\u00ed z toho, \u017ee pokud dojdou v\u0161echny slab-bloky v cache (nap\u0159\u00edklad p\u0159i opakovan\u00e9m otev\u00edr\u00e1n\u00ed souboru), syst\u00e9m p\u0159id\u011blov\u00e1n\u00ed pam\u011bti pou\u017eije voln\u00e9 str\u00e1nky pam\u011bti, k nim\u017e m\u00e1 \u00fato\u010dn\u00edk p\u0159\u00edstup, k vytvo\u0159en\u00ed nov\u00e9ho slab-bloku a v\u0161echny nov\u00e9 souborov\u00e9 struktury za\u010dnou b\u00fdt um\u00edst\u011bny v tomto bloku. Odpov\u00eddaj\u00edc\u00edm zp\u016fsobem se n\u011bkter\u00e9 souborov\u00e9 struktury dostanou do pam\u011b\u0165ov\u00fdch str\u00e1nek, kter\u00e9 m\u016f\u017ee \u010d\u00edst a zapisovat \u00fato\u010dn\u00edk. Vyu\u017eit\u00ed se pak redukuje na zaji\u0161t\u011bn\u00ed, \u017ee pot\u0159ebn\u00fd soubor se dostane do souborov\u00e9 cache a nahrazen\u00ed pole f_mode ve spojen\u00fdch souborov\u00fdch struktur\u00e1ch, kter\u00e9 ur\u010duje pr\u00e1va p\u0159\u00edstupu, co\u017e umo\u017e\u0148uje u\u010dinit po\u017eadovan\u00fd syst\u00e9mov\u00fd soubor zapisovateln\u00fdm, nap\u0159\u00edklad \/etc\/passwd. \u0412 \u0438\u043d\u0442\u0435\u0440\u0444\u0435\u0439\u0441\u0435 \u0430\u0441\u0438\u043d\u0445\u0440\u043e\u043d\u043d\u043e\u0433\u043e \u0432\u0432\u043e\u0434\u0430\/\u0432\u044b\u0432\u043e\u0434\u0430 io_uring, \u043f\u0440\u0435\u0434\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u043c\u043e\u043c \u044f\u0434\u0440\u043e\u043c Linux, \u0432\u044b\u044f\u0432\u043b\u0435\u043d\u0430 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c (CVE-2024-0582), \u043f\u043e\u0437\u0432\u043e\u043b\u044f\u044e\u0449\u0430\u044f \u043d\u0435\u043f\u0440\u0438\u0432\u0438\u043b\u0435\u0433\u0438\u0440\u043e\u0432\u0430\u043d\u043d\u043e\u043c\u0443 \u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u0442\u0435\u043b\u044e \u043f\u043e\u043b\u0443\u0447\u0438\u0442\u044c \u043f\u0440\u0430\u0432\u0430 root \u0432 \u0441\u0438\u0441\u0442\u0435\u043c\u0435. \u0414\u043b\u044f \u044d\u043a\u0441\u043f\u043b\u0443\u0430\u0442\u0430\u0446\u0438\u0438 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438 \u0434\u043e\u0441\u0442\u0430\u0442\u043e\u0447\u043d\u043e \u043e\u0431\u044b\u0447\u043d\u043e\u0433\u043e \u043b\u043e\u043a\u0430\u043b\u044c\u043d\u043e\u0433\u043e \u0434\u043e\u0441\u0442\u0443\u043f\u0430 \u043a \u0441\u0438\u0441\u0442\u0435\u043c\u0435, \u0431\u0435\u0437 \u043d\u0435\u043e\u0431\u0445\u043e\u0434\u0438\u043c\u043e\u0441\u0442\u0438 \u043c\u0430\u043d\u0438\u043f\u0443\u043b\u044f\u0446\u0438\u0439 \u0441 \u043f\u0440\u043e\u0441\u0442\u0440\u0430\u043d\u0441\u0442\u0432\u0430\u043c\u0438 \u0438\u043c\u0451\u043d. \u0412 \u043d\u0430\u0441\u0442\u043e\u044f\u0449\u0435\u0435 \u0432\u0440\u0435\u043c\u044f \u043f\u0443\u0431\u043b\u0438\u0447\u043d\u043e \u0434\u043e\u0441\u0442\u0443\u043f\u0435\u043d \u0440\u0430\u0431\u043e\u0442\u0430\u044e\u0449\u0438\u0439 \u044d\u043a\u0441\u043f\u043b\u043e\u0438\u0442, \u0430 \u0442\u0430\u043a\u0436\u0435 \u043f\u043e\u0434\u0440\u043e\u0431\u043d\u043e \u043e\u043f\u0438\u0441\u0430\u043d\u0430 \u0432\u0442\u043e\u0440\u0430\u044f \u0442\u0435\u0445\u043d\u0438\u043a\u0430 \u044d\u043a\u0441\u043f\u043b\u0443\u0430\u0442\u0430\u0446\u0438\u0438 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438. \u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u0432\u044b\u0437\u0432\u0430\u043d\u0430 \u043e\u0431\u0440\u0430\u0449\u0435\u043d\u0438\u0435\u043c \u043a \u0443\u0436\u0435 \u043e\u0441\u0432\u043e\u0431\u043e\u0436\u0434\u0451\u043d\u043d\u043e\u043c\u0443 […]<\/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-114696","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\udd47Zranitelnost v subsyst\u00e9mu io_uring, kter\u00e1 umo\u017e\u0148uje z\u00edskat privilegium root | ProHoster","description":"V rozhran\u00ed asynchronn\u00edho vstupu\/v\u00fdstupu io_uring, poskytovan\u00e9m j\u00e1drem Linux, byla odhalena zranitelnost (CVE-2024-0582), kter\u00e1 umo\u017e\u0148uje nepriviligovan\u00e9mu u\u017eivateli z\u00edskat pr\u00e1va root v syst\u00e9mu.","canonical_url":"https:\/\/prohoster.info\/cs\/blog\/news\/uyazvimost-v-podsisteme-io_uring-pozvolyayushhaya-poluchit-privilegii-root","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\u044c \u0432 \u043f\u043e\u0434\u0441\u0438\u0441\u0442\u0435\u043c\u0435 io_uring, \u043f\u043e\u0437\u0432\u043e\u043b\u044f\u044e\u0449\u0430\u044f \u043f\u043e\u043b\u0443\u0447\u0438\u0442\u044c \u043f\u0440\u0438\u0432\u0438\u043b\u0435\u0433\u0438\u0438 root | ProHoster","og:description":"\u0412 \u0438\u043d\u0442\u0435\u0440\u0444\u0435\u0439\u0441\u0435 \u0430\u0441\u0438\u043d\u0445\u0440\u043e\u043d\u043d\u043e\u0433\u043e \u0432\u0432\u043e\u0434\u0430\/\u0432\u044b\u0432\u043e\u0434\u0430 io_uring, \u043f\u0440\u0435\u0434\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u043c\u043e\u043c \u044f\u0434\u0440\u043e\u043c Linux, \u0432\u044b\u044f\u0432\u043b\u0435\u043d\u0430 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c (CVE-2024-0582), \u043f\u043e\u0437\u0432\u043e\u043b\u044f\u044e\u0449\u0430\u044f \u043d\u0435\u043f\u0440\u0438\u0432\u0438\u043b\u0435\u0433\u0438\u0440\u043e\u0432\u0430\u043d\u043d\u043e\u043c\u0443 \u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u0442\u0435\u043b\u044e \u043f\u043e\u043b\u0443\u0447\u0438\u0442\u044c \u043f\u0440\u0430\u0432\u0430 root \u0432 \u0441\u0438\u0441\u0442\u0435\u043c\u0435.","og:url":"https:\/\/prohoster.info\/cs\/blog\/news\/uyazvimost-v-podsisteme-io_uring-pozvolyayushhaya-poluchit-privilegii-root","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":"2024-04-01T10:25:54+00:00","article:modified_time":"2024-04-01T10:25:54+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\/114696","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=114696"}],"version-history":[{"count":0,"href":"https:\/\/prohoster.info\/cs\/wp-json\/wp\/v2\/posts\/114696\/revisions"}],"wp:attachment":[{"href":"https:\/\/prohoster.info\/cs\/wp-json\/wp\/v2\/media?parent=114696"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/prohoster.info\/cs\/wp-json\/wp\/v2\/categories?post=114696"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/prohoster.info\/cs\/wp-json\/wp\/v2\/tags?post=114696"}],"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":"