{"id":170863,"date":"2026-05-18T12:24:54","date_gmt":"2026-05-18T10:24:54","guid":{"rendered":"https:\/\/prohoster.info\/blog\/novosti-interneta\/v-linux-raskryta-novaya-lpe-uyazvimost-fragnesia-pozvolyayushhaya-lokalnomu-polzovatelyu-poluchit-root"},"modified":"2026-05-18T12:24:54","modified_gmt":"2026-05-18T10:24:54","slug":"v-linux-raskryta-novaya-lpe-uyazvimost-fragnesia-pozvolyayushhaya-lokalnomu-polzovatelyu-poluchit-root","status":"publish","type":"post","link":"https:\/\/prohoster.info\/hr\/blog\/news\/v-linux-raskryta-novaya-lpe-uyazvimost-fragnesia-pozvolyayushhaya-lokalnomu-polzovatelyu-poluchit-root","title":{"rendered":"U Linuxu otkrivena nova LPE ranjivost Fragnesia, koja omogu\u0107uje lokalnom korisniku da dobije root pristup","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"

U Linux kernelu otkrivena je nova ranjivost lokalnog eskaliranja privilegija pod nazivom Fragnesia<\/strong> i identifikatorom CVE-2026-46300<\/strong>. Problem se odnosi na istu klasu napada na page cache kao i nedavno raspravljani Copy Fail i Dirty Frag, ali nije ponovna objava stare gre\u0161ke: radi se o zasebnom defektu u kodu XFRM ESP-in-TCP<\/strong>.<\/p>\n

Ranjivost je otkrio istra\u017eiva\u010d William Bowling<\/strong> iz tima V12 Security<\/strong>. Prema objavljenom opisu, Fragnesia omogu\u0107uje neprivilegiranom lokalnom korisniku da mijenja sadr\u017eaj datoteka koje su samo za \u010ditanje u memoriji page cache i na taj na\u010din izvr\u0161ava kod s pravima root. Za razliku od mnogih starih LPE eksploita, napad ne zahtijeva utrku i istra\u017eiva\u010di ga opisuje kao deterministi\u010dkog.<\/p>\n

Tehni\u010dki, problem je u tome \u0161to je prilikom spajanja mre\u017enih spremnika jezgra mogla izgubiti oznaku da je fragment podataka \"zajedni\u010dki\" i povezan s vanjskom stranicom memorije, uklju\u010duju\u0107i page cache. U predlo\u017eenom ispravku to se opisuje kao gre\u0161ka u skb_try_coalesce(): prilikom premje\u0161tanja paged fragments iz jednog sk_buff-a u drugi, oznaka SKBFL_SHARED_FRAG nije o\u010duvana. Kao rezultat, kasniji kod ESP mogao je pogre\u0161no smatrati da je spremnik siguran za promjenu.<\/p>\n

Prakti\u010dni u\u010dinak je u tome \u0161to su podaci, koji su ranije stavljeni u TCP red iz datoteke, nakon prebacivanja soketa u na\u010din espintcp mogli biti obra\u0111ivani od strane jezgre kao ESP \u0161ifrat. Prilikom de\u0161ifriranja AES-GCM bajtovi su se mijenjali direktno u stranici page cache povezanoj s datotekom. To ne mijenja datoteku na disku, ali mijenja njezinu reprezentaciju u memoriji prije nego \u0161to se stranica izbaci iz predmemorije.<\/p>\n

U objavljenoj demonstraciji napada, kao cilj je kori\u0161tena \/usr\/bin\/su: eksploatacija je modificirala prve bajtove binarne datoteke u page cache i zatim pokrenula promijenjenu u memoriji kopiju, dobivaju\u0107i shell s pravima root. Izvorna datoteka na disku ostala je nepromijenjena, \u0161to \u010dini problem posebno neugodnim za dijagnosticiranje: tragovi eksploatacije mogu nestati nakon \u010di\u0161\u0107enja page cache-a ili ponovnog pokretanja.<\/p>\n

Fragnesia se pojavila manje od tjedan dana nakon Dirty Frag. U V12 nagla\u0161avaju da se radi o zasebnoj gre\u0161ci na istoj povr\u0161ini napada \u2013 ESP\/XFRM, a ne o preimenovanju ve\u0107 ispravljene ranjivosti. Phoronix tako\u0111er napominje da je u trenutku objave bio dostupan proof-of-concept, a ispravak je bio mali patch za net\/core\/skbuff.c, koji jo\u0161 nije odmah dospio u glavne grane jezgre.<\/p>\n

<\/p>\n

Canonical je dodijelio CVE-2026-46300<\/a> visok prioritet za Ubuntu, navode\u0107i razlog kao \u201etrivial local privilege escalation\u201c. Na stranici sigurnosti Ubuntua za pogo\u0111ene jezgre na dan a\u017euriranja 13. svibnja status je bio \u201eNeeds evaluation\u201c, a u napomeni je posebno navedeno da je problem tako\u0111er prisutan u ESP-modulu jezgre i da ga se mo\u017ee privremeno ubla\u017eiti na isti na\u010din kao i Dirty Frag.<\/p>\n

<\/noindex><\/noindex> <\/p>\n

Debian Security Tracker<\/a> u trenutku pregleda ozna\u010dava ranjivima jezgre u granama bullseye, bookworm, trixie, forky i sid; za paket linux u unstable fiksna verzija jo\u0161 nije bila navedena.<\/p>\n

<\/noindex> <\/p>\n

Privremena mjera za\u0161tite ostaje ista kao i za Dirty Frag: onemogu\u0107iti u\u010ditavanje modula<\/a> esp4, esp6 i rxrpc, ako nisu potrebni sustavu. To mo\u017ee naru\u0161iti rad IPsec tunela na \u010dvorovima gdje se koriste kernel ESP, strongSwan, Libreswan ili sli\u010dne konfiguracije, stoga se tu mjeru na VPN-gateways treba primijeniti tek nakon procjene posljedica.<\/p>\n

<\/noindex> <\/p>\n

Primjer privremenog ubla\u017eavanja za administratore:<\/p>\n

sudo sh -c \"printf 'install esp4 \/bin\/falseninstall esp6 \/bin\/falseninstall rxrpc \/bin\/falsen' > \/etc\/modprobe.d\/dirtyfrag.conf\" sudo rmmod esp4 esp6 rxrpc 2>\/dev\/null || true <\/p>\n

Ako postoji sumnja da je sustav ve\u0107 mogao biti napadnut, sama blokada modula nije dovoljna: budu\u0107i da javna demonstracija mijenja izvr\u0161nu datoteku upravo u page cache-u, administratori preporu\u010duju \u010di\u0161\u0107enje cache-a stranica ili ponovni pokretanje sustava nakon primjene mjera za\u0161tite. CloudLinux izri\u010dito napominje da nakon eksploatacije \/usr\/bin\/su mo\u017ee ostati izmijenjen u memoriji do izbacivanja odgovaraju\u0107ih stranica.<\/p>\n

Za uklanjanje privremenog pravila nakon instalacije ispravljene jezgre mo\u017ee se ukloniti stvorena datoteka:<\/p>\n

sudo rm \/etc\/modprobe.d\/dirtyfrag.conf <\/p>\n

Glavna preporuka ostaje standardna: instalirati ispravljenu jezgru od svog distributera i ponovo pokrenuti sustav. Prije a\u017euriranja najve\u0107i rizik nose vi\u0161ekorisni\u010dki poslu\u017eitelji, CI-trka\u010di, shared hosting, kontejnerske build-farme i bilo koje ma\u0161ine gdje neprivilegirani ili djelomi\u010dno povjerljivi korisnici mogu izvr\u0161avati lokalni kod.<\/p>\n

Izvor: linux.org.ru<\/a><\/p>","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":"

\u0412 \u044f\u0434\u0440\u0435 Linux \u0440\u0430\u0441\u043a\u0440\u044b\u0442\u0430 \u043e\u0447\u0435\u0440\u0435\u0434\u043d\u0430\u044f \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u043b\u043e\u043a\u0430\u043b\u044c\u043d\u043e\u0433\u043e \u043f\u043e\u0432\u044b\u0448\u0435\u043d\u0438\u044f \u043f\u0440\u0438\u0432\u0438\u043b\u0435\u0433\u0438\u0439, \u043f\u043e\u043b\u0443\u0447\u0438\u0432\u0448\u0430\u044f \u043d\u0430\u0437\u0432\u0430\u043d\u0438\u0435 Fragnesia \u0438 \u0438\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440 CVE-2026-46300. \u041f\u0440\u043e\u0431\u043b\u0435\u043c\u0430 \u043e\u0442\u043d\u043e\u0441\u0438\u0442\u0441\u044f \u043a \u0442\u043e\u043c\u0443 \u0436\u0435 \u043a\u043b\u0430\u0441\u0441\u0443 \u0430\u0442\u0430\u043a \u043d\u0430 page cache, \u0447\u0442\u043e \u0438 \u043d\u0435\u0434\u0430\u0432\u043d\u043e \u043e\u0431\u0441\u0443\u0436\u0434\u0430\u0432\u0448\u0438\u0435\u0441\u044f Copy Fail \u0438 Dirty Frag, \u043d\u043e \u043d\u0435 \u044f\u0432\u043b\u044f\u0435\u0442\u0441\u044f \u043f\u043e\u0432\u0442\u043e\u0440\u043d\u043e\u0439 \u043f\u0443\u0431\u043b\u0438\u043a\u0430\u0446\u0438\u0435\u0439 \u0441\u0442\u0430\u0440\u043e\u0439 \u043e\u0448\u0438\u0431\u043a\u0438: \u0440\u0435\u0447\u044c \u0438\u0434\u0451\u0442 \u043e\u0431 \u043e\u0442\u0434\u0435\u043b\u044c\u043d\u043e\u043c \u0434\u0435\u0444\u0435\u043a\u0442\u0435 \u0432 \u043a\u043e\u0434\u0435 XFRM ESP-in-TCP. \u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u043e\u0431\u043d\u0430\u0440\u0443\u0436\u0438\u043b \u0438\u0441\u0441\u043b\u0435\u0434\u043e\u0432\u0430\u0442\u0435\u043b\u044c William Bowling […]<\/p>\n","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"author":8,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[702],"tags":[],"class_list":["post-170863","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\udd47U Linuxu je otkrivena nova LPE ranjivost Fragnesia koja lokalnom korisniku omogu\u0107ava dobivanje root privilegija | ProHoster","description":"U kernelu Linux otkrivena je nova ranjivost lokalnog pove\u0107anja privilegija pod nazivom Fragnesia s identifikatorom CVE-2026-46300.","canonical_url":"https:\/\/prohoster.info\/hr\/blog\/news\/v-linux-raskryta-novaya-lpe-uyazvimost-fragnesia-pozvolyayushhaya-lokalnomu-polzovatelyu-poluchit-root","robots":"max-image-preview:large","keywords":"","webmasterTools":{"miscellaneous":""},"schema":null,"og:locale":"hr_HR","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\u0412 Linux \u0440\u0430\u0441\u043a\u0440\u044b\u0442\u0430 \u043d\u043e\u0432\u0430\u044f LPE-\u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c Fragnesia, \u043f\u043e\u0437\u0432\u043e\u043b\u044f\u044e\u0449\u0430\u044f \u043b\u043e\u043a\u0430\u043b\u044c\u043d\u043e\u043c\u0443 \u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u0442\u0435\u043b\u044e \u043f\u043e\u043b\u0443\u0447\u0438\u0442\u044c root | ProHoster","og:description":"\u0412 \u044f\u0434\u0440\u0435 Linux \u0440\u0430\u0441\u043a\u0440\u044b\u0442\u0430 \u043e\u0447\u0435\u0440\u0435\u0434\u043d\u0430\u044f \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u043b\u043e\u043a\u0430\u043b\u044c\u043d\u043e\u0433\u043e \u043f\u043e\u0432\u044b\u0448\u0435\u043d\u0438\u044f \u043f\u0440\u0438\u0432\u0438\u043b\u0435\u0433\u0438\u0439, \u043f\u043e\u043b\u0443\u0447\u0438\u0432\u0448\u0430\u044f \u043d\u0430\u0437\u0432\u0430\u043d\u0438\u0435 Fragnesia \u0438 \u0438\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440 CVE-2026-46300.","og:url":"https:\/\/prohoster.info\/hr\/blog\/news\/v-linux-raskryta-novaya-lpe-uyazvimost-fragnesia-pozvolyayushhaya-lokalnomu-polzovatelyu-poluchit-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":"2026-05-18T10:24:54+00:00","article:modified_time":"2026-05-18T10:24:54+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\/hr\/wp-json\/wp\/v2\/posts\/170863","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/prohoster.info\/hr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/prohoster.info\/hr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/prohoster.info\/hr\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/prohoster.info\/hr\/wp-json\/wp\/v2\/comments?post=170863"}],"version-history":[{"count":0,"href":"https:\/\/prohoster.info\/hr\/wp-json\/wp\/v2\/posts\/170863\/revisions"}],"wp:attachment":[{"href":"https:\/\/prohoster.info\/hr\/wp-json\/wp\/v2\/media?parent=170863"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/prohoster.info\/hr\/wp-json\/wp\/v2\/categories?post=170863"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/prohoster.info\/hr\/wp-json\/wp\/v2\/tags?post=170863"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}