{"id":172665,"date":"2026-05-19T00:24:34","date_gmt":"2026-05-18T22:24:34","guid":{"rendered":"https:\/\/prohoster.info\/blog\/novosti-interneta\/dirtydecrypt-ocherednaya-uyazvimost-klassa-copy-fail-predostavlyayushhaya-prava-root-v-linux"},"modified":"2026-05-19T00:24:34","modified_gmt":"2026-05-18T22:24:34","slug":"dirtydecrypt-ocherednaya-uyazvimost-klassa-copy-fail-predostavlyayushhaya-prava-root-v-linux","status":"publish","type":"post","link":"https:\/\/prohoster.info\/sk\/blog\/news\/dirtydecrypt-ocherednaya-uyazvimost-klassa-copy-fail-predostavlyayushhaya-prava-root-v-linux","title":{"rendered":"DirtyDecrypt \u2014 \u010fal\u0161ia zranite\u013enos\u0165 typu Copy Fail, poskytuj\u00faca pr\u00e1va root v Linuxe","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"

V jadre Linux bola objaven\u00e1 zranite\u013enos\u0165, podobn\u00e1 zranite\u013enostiam Copy Fail, Dirty Frag a Fragnesia, ktor\u00e1 umo\u017e\u0148uje neprivilegovan\u00e9mu pou\u017e\u00edvate\u013eovi z\u00edska\u0165 pr\u00e1va root prep\u00edsan\u00edm \u00fadajov vo str\u00e1nkovom cache. Zranite\u013enosti bolo pridelen\u00e9 k\u00f3dov\u00e9 meno DirtyDecrypt (probl\u00e9m je tie\u017e spom\u00ednan\u00fd pod menom DirtyCBC). Je dostupn\u00fd prototyp exploit. <\/p>\n

CVE identifik\u00e1tor nie je v pozn\u00e1mke k exploit-u spom\u00ednan\u00fd, uv\u00e1dza sa len to, \u017ee v\u00fdskumn\u00edci objavili probl\u00e9m 9. m\u00e1ja, po \u010dom informovali v\u00fdvoj\u00e1rov jadra, ktor\u00ed odpovedali, \u017ee ich n\u00e1lez duplicitne nahlasuje u\u017e opraven\u00fa zranite\u013enos\u0165. Ke\u010f\u017ee z\u00e1plata bola u\u017e zahrnut\u00e1 v jadre, v\u00fdskumn\u00edci sa rozhodli zverejni\u0165 ich vyvinut\u00fd exploit. S\u00fadruh pod\u013ea popisu vo vn\u00fatri exploit-u pou\u017e\u00edva zranite\u013enos\u0165 CVE-2026-31635, \u00faprava pre ktor\u00fa bola prijat\u00e1 do jadra v apr\u00edli a je s\u00fa\u010das\u0165ou vetvy 7.0.0 a zostavenia z 18. apr\u00edla vo vydan\u00ed 6.18.23. Probl\u00e9m sa objavuje od jadra 6.16. <\/p>\n

Rovnako ako v pr\u00edpade s\u00e9rie zranite\u013enost\u00ed Dirty Frag sa nov\u00e1 zranite\u013enos\u0165 nach\u00e1dza v ovl\u00e1da\u010di RxRPC, ktor\u00fd implementuje rodinu soketov AF_RXRPC a rovnomenn\u00fd RPC protokol funguj\u00faci nad UDP. Probl\u00e9m je sp\u00f4soben\u00fd chybou pri overovan\u00ed ve\u013ekosti \u00fadajov vo funkcii rxgk_verify_response() \u2014 namiesto kontroly \u201eif (auth_len > len)\u201c bol v k\u00f3de uveden\u00fd \u201eif (auth_len < len)\u201c, \u010do viedlo k prihr\u00e1vaniu \u00fadajov s ve\u013ekos\u0165ou v\u00e4\u010d\u0161ou ako pr\u00edpustn\u00e9 do funkcie rxgk_decrypt_skb(). Pri vykon\u00e1van\u00ed funkcie rxgk_decrypt_skb() bola de\u0161ifr\u00e1cia \u00fadajov vykonan\u00e1 s priamej substit\u00facii zmien do str\u00e1nekov\u00e9ho cache, aby sa vyl\u00fa\u010dila nadbyto\u010dn\u00e1 vyrovn\u00e1vacia pam\u00e4\u0165. V d\u00f4sledku nespr\u00e1vneho overenia ve\u013ekosti vznikla mo\u017enos\u0165 prep\u00edsania \u00fadajov v str\u00e1nkovom cache na vybranom posunut\u00ed. <\/p>\n

Exploat\u00e1cia zranite\u013enosti spo\u010d\u00edva v pre\u010d\u00edtan\u00ed s\u00faboru programu s pr\u00edznakom suid root (na jeho usadenie v str\u00e1nkovom cache) a nahraden\u00ed \u010dasti k\u00f3du programu v str\u00e1nkovom cache k\u00f3dom pre spustenie \/usr\/bin\/sh. N\u00e1sledn\u00e9 spustenie programu sp\u00f4sob\u00ed, \u017ee do pam\u00e4ti bude na\u010d\u00edtan\u00fd nie p\u00f4vodn\u00fd spustite\u013en\u00fd s\u00fabor z \u00falo\u017eiska, ale zmenen\u00e1 k\u00f3pia zo str\u00e1nkov\u00e9ho cache. Ako suid programy s\u00fa v exploite zahrnut\u00e9 mo\u017enosti pou\u017eitia \u201e\/usr\/bin\/su\u201c, \u201e\/bin\/su\u201c, \u201e\/usr\/bin\/mount\u201c, \u201e\/usr\/bin\/passwd\u201c a \u201e\/usr\/bin\/chsh\u201c. <\/p>\n

Na vyu\u017eitie zranite\u013enosti pri zostaven\u00ed jadra mus\u00ed by\u0165 akt\u00edvna mo\u017enos\u0165 CONFIG_RXGK a pre automatick\u00e9 na\u010d\u00edtanie je k dispoz\u00edcii modul jadra rxrpc.ko (v niektor\u00fdch syst\u00e9moch sa nevytv\u00e1ra). Stav odstr\u00e1nenia zranite\u013enost\u00ed v distrib\u00faci\u00e1ch m\u00f4\u017eete pos\u00fadi\u0165 na t\u00fdchto str\u00e1nkach: Debian, Ubuntu, SUSE\/openSUSE, RHEL, Arch, Fedora. Ako obch\u00e1dzaj\u00face opatrenie na ochranu m\u00f4\u017eete zablokova\u0165 na\u010d\u00edtanie modulu jadra rxrpc: <\/p>\n

sh -c 'printf 'install rxrpc \/bin\/false\n' > \/etc\/modprobe.d\/dirtydecrypt.conf; rmmod rxrpc 2>\/dev\/null; true' <\/p>\n

\u010ealej m\u00f4\u017eeme spomen\u00fa\u0165 zverejnenie v mailing liste v\u00fdvoj\u00e1rov kernela Linux patchov, ktor\u00e9 \u00faplne vyp\u00ednaj\u00fa v crypto API (AF_ALG) optimaliz\u00e1cie vyu\u017e\u00edvaj\u00face priame pr\u00edstupovanie do str\u00e1nkov\u00e9ho cache pri de\u0161ifrovan\u00ed pomocou algoritmov \u201eskcipher\u201c a \u201eaead\u201c. Optimaliz\u00e1cie vylu\u010duj\u00fa nadbyto\u010dn\u00e9 vyrovn\u00e1vanie \u00fadajov, ale vytv\u00e1raj\u00fa rizik\u00e1 vzniku z\u00e1va\u017en\u00fdch zranite\u013enost\u00ed. Predpoklad\u00e1 sa, \u017ee ich vypnutie povedie iba k nepatrn\u00e9mu zn\u00ed\u017eeniu v\u00fdkonu kv\u00f4li vzniku dodato\u010dnej oper\u00e1cie kop\u00edrovania do samostatn\u00e9ho vyrovn\u00e1vacieho z\u00e1sobn\u00edka. Patche boli prijat\u00e9 sprievodcom subsyst\u00e9mu crypto API a zaraden\u00e9 do vetvy \u201ecryptodev\u201c, v ktorej sa rozv\u00edjaj\u00fa mo\u017enosti pre prevod do hlavnej \u010dasti bud\u00facich vydan\u00ed kernela Linux.
\n
Zdroj: opennet.ru<\/a> <\/p>","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":"

\u0412 \u044f\u0434\u0440\u0435 Linux \u0432\u044b\u044f\u0432\u043b\u0435\u043d\u0430 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c, \u043f\u043e \u0430\u043d\u0430\u043b\u043e\u0433\u0438\u0438 \u0441 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044f\u043c\u0438 Copy Fail, Dirty Frag \u0438 Fragnesia \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, \u043f\u0435\u0440\u0435\u0437\u0430\u043f\u0438\u0441\u0430\u0432 \u0434\u0430\u043d\u043d\u044b\u0435 \u0432 \u0441\u0442\u0440\u0430\u043d\u0438\u0447\u043d\u043e\u043c \u043a\u044d\u0448\u0435. \u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438 \u043f\u0440\u0438\u0441\u0432\u043e\u0435\u043d\u043e \u043a\u043e\u0434\u043e\u0432\u043e\u0435 \u0438\u043c\u044f DirtyDecrypt (\u043f\u0440\u043e\u0431\u043b\u0435\u043c\u0430 \u0442\u0430\u043a\u0436\u0435 \u0443\u043f\u043e\u043c\u0438\u043d\u0430\u0435\u0442\u0441\u044f \u043f\u043e\u0434 \u0438\u043c\u0435\u043d\u0435\u043c DirtyCBC). \u0414\u043e\u0441\u0442\u0443\u043f\u0435\u043d \u043f\u0440\u043e\u0442\u043e\u0442\u0438\u043f \u044d\u043a\u0441\u043f\u043b\u043e\u0438\u0442\u0430. CVE-\u0438\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440 \u0432 \u043f\u0440\u0438\u043c\u0435\u0447\u0430\u043d\u0438\u0438 \u043a \u044d\u043a\u0441\u043f\u043b\u043e\u0438\u0442\u0443 \u043d\u0435 \u0443\u043f\u043e\u043c\u0438\u043d\u0430\u0435\u0442\u0441\u044f, \u0443\u043a\u0430\u0437\u0430\u043d\u043e \u043b\u0438\u0448\u044c, \u0447\u0442\u043e \u0438\u0441\u0441\u043b\u0435\u0434\u043e\u0432\u0430\u0442\u0435\u043b\u0438 \u0432\u044b\u044f\u0432\u0438\u043b\u0438 \u043f\u0440\u043e\u0431\u043b\u0435\u043c\u0443 9 \u043c\u0430\u044f, […]<\/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-172665","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\udd47DirtyDecrypt \u2014 \u010fal\u0161ia zranite\u013enos\u0165 triedy Copy Fail, poskytuj\u00faca pr\u00e1va root v Linuxe | ProHoster","description":"V jadre Linux bola zisten\u00e1 zranite\u013enos\u0165, podobn\u00e1 zranite\u013enostiam Copy Fail, Dirty Frag a Fragnesia, ktor\u00e1 umo\u017e\u0148uje nepovolen\u00e9mu pou\u017e\u00edvate\u013eovi z\u00edska\u0165 pr\u00e1va root prep\u00edsan\u00edm \u00fadajov v str\u00e1nkovom cache.","canonical_url":"https:\/\/prohoster.info\/sk\/blog\/news\/dirtydecrypt-ocherednaya-uyazvimost-klassa-copy-fail-predostavlyayushhaya-prava-root-v-linux","robots":"max-image-preview:large","keywords":"","webmasterTools":{"miscellaneous":""},"schema":null,"og:locale":"sk_SK","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\udd47DirtyDecrypt \u2014 \u043e\u0447\u0435\u0440\u0435\u0434\u043d\u0430\u044f \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u043a\u043b\u0430\u0441\u0441\u0430 Copy Fail, \u043f\u0440\u0435\u0434\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u044e\u0449\u0430\u044f \u043f\u0440\u0430\u0432\u0430 root \u0432 Linux | 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, \u043f\u043e \u0430\u043d\u0430\u043b\u043e\u0433\u0438\u0438 \u0441 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044f\u043c\u0438 Copy Fail, Dirty Frag \u0438 Fragnesia \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, \u043f\u0435\u0440\u0435\u0437\u0430\u043f\u0438\u0441\u0430\u0432 \u0434\u0430\u043d\u043d\u044b\u0435 \u0432 \u0441\u0442\u0440\u0430\u043d\u0438\u0447\u043d\u043e\u043c \u043a\u044d\u0448\u0435.","og:url":"https:\/\/prohoster.info\/sk\/blog\/news\/dirtydecrypt-ocherednaya-uyazvimost-klassa-copy-fail-predostavlyayushhaya-prava-root-v-linux","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":"2026-05-18T22:24:34+00:00","article:modified_time":"2026-05-18T22:24:34+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\/sk\/wp-json\/wp\/v2\/posts\/172665","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/prohoster.info\/sk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/prohoster.info\/sk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/prohoster.info\/sk\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/prohoster.info\/sk\/wp-json\/wp\/v2\/comments?post=172665"}],"version-history":[{"count":0,"href":"https:\/\/prohoster.info\/sk\/wp-json\/wp\/v2\/posts\/172665\/revisions"}],"wp:attachment":[{"href":"https:\/\/prohoster.info\/sk\/wp-json\/wp\/v2\/media?parent=172665"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/prohoster.info\/sk\/wp-json\/wp\/v2\/categories?post=172665"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/prohoster.info\/sk\/wp-json\/wp\/v2\/tags?post=172665"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}