{"id":110411,"date":"2023-10-04T08:10:45","date_gmt":"2023-10-04T06:10:45","guid":{"rendered":"https:\/\/prohoster.info\/?p=110411"},"modified":"2023-10-04T08:10:45","modified_gmt":"2023-10-04T06:10:45","slug":"uyazvimost-v-glibc-ld-so-pozvolyayushhaya-poluchit-prava-root-v-sisteme","status":"publish","type":"post","link":"https:\/\/prohoster.info\/sk\/blog\/news\/uyazvimost-v-glibc-ld-so-pozvolyayushhaya-poluchit-prava-root-v-sisteme","title":{"rendered":"Zranite\u013enos\u0165 v Glibc ld.so, ktor\u00e1 umo\u017e\u0148uje z\u00edska\u0165 pr\u00e1va root v syst\u00e9me","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"<p>Spolo\u010dnos\u0165 Qualys odhalila nebezpe\u010dn\u00fa zranite\u013enos\u0165 (CVE-2023-4911) v linkeri ld.so, ktor\u00fd je dod\u00e1van\u00fd ako s\u00fa\u010das\u0165 syst\u00e9movej C kni\u017enice Glibc (GNU libc). Zranite\u013enos\u0165 umo\u017e\u0148uje lok\u00e1lnemu pou\u017e\u00edvate\u013eovi zv\u00fd\u0161i\u0165 svoje opr\u00e1vnenia v syst\u00e9me zadan\u00edm \u0161peci\u00e1lne form\u00e1tovan\u00fdch \u00fadajov do premennej prostredia GLIBC_TUNABLES pred spusten\u00edm spustite\u013en\u00e9ho s\u00faboru s pr\u00edznakom suid root, napr\u00edklad \/usr\/bin\/su.    <\/p>\n<p>Mo\u017enos\u0165 \u00faspe\u0161n\u00e9ho zneu\u017eitia zranite\u013enosti bola demon\u0161trovan\u00e1 na Fedore 37 a 38, Ubuntu 22.04 a 23.04, Debian 12 a 13. Predpoklad\u00e1 sa, \u017ee zranite\u013enos\u0165 sa prejavuje aj v in\u00fdch distrib\u00faci\u00e1ch, ktor\u00e9 pou\u017e\u00edvaj\u00fa Glibc. Distrib\u00facie zalo\u017een\u00e9 na syst\u00e9movej C kni\u017enici Musl, ako je Alpine Linux, nie s\u00fa touto probl\u00e9mom postihnut\u00e9. Zranite\u013enos\u0165 bola odstr\u00e1nen\u00e1 v oprave pridan\u00e9 2. okt\u00f3bra. Sledujte vyd\u00e1vanie aktualiz\u00e1ci\u00ed bal\u00edkov v distrib\u00faci\u00e1ch na str\u00e1nkach Debian, Ubuntu, RHEL, SUSE\/openSUSE, Fedora, Arch, Gentoo, ALT Linux.    <\/p>\n<p>Zranite\u013enos\u0165 bola sp\u00f4soben\u00e1 zmenou, ktor\u00e1 bola vykonan\u00e1 v apr\u00edli 2021 a bola s\u00fa\u010das\u0165ou vydania glibc 2.34. V d\u00f4sledku chyby v k\u00f3de anal\u00fdzy re\u0165azca uvedenej v premennej prostredia GLIBC_TUNABLES, nespr\u00e1vna kombin\u00e1cia parametrov v tejto premennej vedie k prepisovaniu analyzovanej hodnoty mimo pridelen\u00e9ho z\u00e1sobn\u00edka. Probl\u00e9m sa prejavuje, ke\u010f s\u00fa namiesto \u0161tandardn\u00fdch sekvenci\u00ed \u201ename=val\u201c parametre zadan\u00e9 vo forme s dvojit\u00fdm priraden\u00edm \u201ename=name=val\u201c. V tomto pr\u00edpade je priradenie spracovan\u00e9 dvakr\u00e1t, najprv ako \u201ename=name=val\u201c, a potom ako \u201ename=val\u201c. V d\u00f4sledku takejto dvojitej anal\u00fdzy vznik\u00e1 v\u00fdsledok \u201ename=name=val:name=val\u201c, ktor\u00e9ho ve\u013ekos\u0165 presahuje ve\u013ekos\u0165 z\u00e1sobn\u00edka tunestr.      <\/p>\n<p>V\u00fdskumn\u00edci pripravili stabilne funguj\u00faci exploit, ktor\u00fd umo\u017e\u0148uje z\u00edska\u0165 pr\u00e1va root pri pou\u017eit\u00ed takmer s ak\u00fdmko\u013evek programom s pr\u00edznakom suid root. V\u00fdnimku tvoria n\u00e1stroj sudo (men\u00ed hodnotu ELF RUNPATH), n\u00e1stroje chage a passwd vo Federe (chr\u00e1nia ich osobitn\u00e9 pravidl\u00e1 SELinux) a n\u00e1stroj snap-confine v Ubuntu (chr\u00e1nia ich osobitn\u00e9 pravidl\u00e1 AppArmor). Navrhnut\u00e1 met\u00f3da exploit\u00e1cie taktie\u017e nefunguje v RHEL 8 a RHEL 9, hoci tieto vetvy s\u00fa zranite\u013en\u00e9 (na \u00fatok je potrebn\u00e9 vytvorenie in\u00e9ho exploit-u). K\u00f3d exploit-u bude zverejnen\u00fd nesk\u00f4r po celoplo\u0161nom odstr\u00e1nen\u00ed zranite\u013enosti. Skontrolova\u0165 zranite\u013enos\u0165 svojho syst\u00e9mu m\u00f4\u017eete pomocou ni\u017e\u0161ie uveden\u00e9ho pr\u00edkazu, ktor\u00fd v pr\u00edpade probl\u00e9mu skon\u010d\u00ed hav\u00e1riou: env -i \"GLIBC_TUNABLES=glibc.malloc.mxfast=glibc.malloc.mxfast=A\" \"Z=[0;39m`printf '192x' 1`\" \/usr\/bin\/su --help      <\/p>\n<p>Zvl\u00e1\u0161\u0165 sa spom\u00edna odstr\u00e1nenie v Glibc \u010fal\u0161\u00edch dvoch zranite\u013enost\u00ed:  <\/p>\n<ul>\n<li class=\"l\"> CVE-2023-4806 \u2014 pr\u00edstup k u\u017e uvo\u013enenej oblasti pam\u00e4te (use-after-free) vo funkcii getaddrinfo(), prejavuj\u00faci sa, ke\u010f NSS-plugin implementuje iba call-back volania \u201e_gethostbyname2_r\u201c a \u201e_getcanonname_r\u201c, ale nepodporuje volanie \u201e_gethostbyname3_r\u201c. Na exploit\u00e1ciu zranite\u013enosti mus\u00ed DNS-server vr\u00e1ti\u0165 pre po\u017eadovan\u00fd hostite\u013e ve\u013ek\u00e9 mno\u017estvo adries IPv6 a IPv4, \u010do povedie k zr\u00fateniu procesu, ktor\u00fd zavolal funkciu getaddrinfo pre rodinu AF_INET6 pri nastaven\u00ed vlajok AI_CANONNAME, AI_ALL a AI_V4MAPPED.\n<li class=\"l\"> CVE-2023-5156 \u2014 \u00fanik obsahu pam\u00e4te pri volan\u00ed funkcie getaddrinfo pre rodinu adries AF_INET6 so zapnut\u00fdmi vlajkami AI_CANONNAME, AI_ALL a AI_V4MAPPED.        <\/ul>\n<p>Zdroj: <a content=\"nofollow\" rel=\"nofollow\" href=\"https:\/\/www.opennet.ru\/opennews\/art.shtml?num=59867\">opennet.ru<\/a> <\/p>","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":"<p>\u041a\u043e\u043c\u043f\u0430\u043d\u0438\u044f Qualys \u0432\u044b\u044f\u0432\u0438\u043b\u0430 \u043e\u043f\u0430\u0441\u043d\u0443\u044e \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c (CVE-2023-4911) \u0432 \u043a\u043e\u043c\u043f\u043e\u043d\u043e\u0432\u0449\u0438\u043a\u0435 ld.so, \u043f\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u043c\u043e\u043c \u0432 \u0441\u043e\u0441\u0442\u0430\u0432\u0435 \u0441\u0438\u0441\u0442\u0435\u043c\u043d\u043e\u0439 \u0421\u0438-\u0431\u0438\u0431\u043b\u0438\u043e\u0442\u0435\u043a\u0438 Glibc (GNU libc). \u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u043f\u043e\u0437\u0432\u043e\u043b\u044f\u0435\u0442 \u043b\u043e\u043a\u0430\u043b\u044c\u043d\u043e\u043c\u0443 \u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u0442\u0435\u043b\u044e \u043f\u043e\u0434\u043d\u044f\u0442\u044c \u0441\u0432\u043e\u0438 \u043f\u0440\u0438\u0432\u0438\u043b\u0435\u0433\u0438\u0438 \u0432 \u0441\u0438\u0441\u0442\u0435\u043c\u0435 \u0447\u0435\u0440\u0435\u0437 \u0443\u043a\u0430\u0437\u0430\u043d\u0438\u0435 \u0441\u043f\u0435\u0446\u0438\u0430\u043b\u044c\u043d\u043e \u043e\u0444\u043e\u0440\u043c\u043b\u0435\u043d\u043d\u044b\u0445 \u0434\u0430\u043d\u043d\u044b\u0445 \u0432 \u043f\u0435\u0440\u0435\u043c\u0435\u043d\u043d\u043e\u0439 \u043e\u043a\u0440\u0443\u0436\u0435\u043d\u0438\u044f GLIBC_TUNABLES \u043f\u0435\u0440\u0435\u0434 \u0437\u0430\u043f\u0443\u0441\u043a\u043e\u043c \u0438\u0441\u043f\u043e\u043b\u043d\u044f\u0435\u043c\u043e\u0433\u043e \u0444\u0430\u0439\u043b\u0430 \u0441 \u0444\u043b\u0430\u0433\u043e\u043c suid root, \u043d\u0430\u043f\u0440\u0438\u043c\u0435\u0440, \/usr\/bin\/su. \u0412\u043e\u0437\u043c\u043e\u0436\u043d\u043e\u0441\u0442\u044c \u0443\u0441\u043f\u0435\u0448\u043d\u043e\u0439 \u044d\u043a\u0441\u043f\u043b\u0443\u0430\u0442\u0430\u0446\u0438\u0438 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438 \u043f\u0440\u043e\u0434\u0435\u043c\u043e\u043d\u0441\u0442\u0440\u0438\u0440\u043e\u0432\u0430\u043d\u0430 \u0432 Fedora 37 \u0438 38, [&hellip;]<\/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-110411","post","type-post","status-publish","format-standard","hentry","category-news"],"aioseo_notices":[],"aioseo_head":"\n\t\t<!-- All in One SEO 5.0.4 - aioseo.com -->\n\t<meta name=\"description\" content=\"\u041a\u043e\u043c\u043f\u0430\u043d\u0438\u044f Qualys \u0432\u044b\u044f\u0432\u0438\u043b\u0430 \u043e\u043f\u0430\u0441\u043d\u0443\u044e \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c (CVE-2023-4911) \u0432 \u043a\u043e\u043c\u043f\u043e\u043d\u043e\u0432\u0449\u0438\u043a\u0435 ld.so, \u043f\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u043c\u043e\u043c \u0432 \u0441\u043e\u0441\u0442\u0430\u0432\u0435 \u0441\u0438\u0441\u0442\u0435\u043c\u043d\u043e\u0439 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content=\"\ud83e\udd47\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u0432 Glibc ld.so, \u043f\u043e\u0437\u0432\u043e\u043b\u044f\u044e\u0449\u0430\u044f \u043f\u043e\u043b\u0443\u0447\u0438\u0442\u044c \u043f\u0440\u0430\u0432\u0430 root \u0432 \u0441\u0438\u0441\u0442\u0435\u043c\u0435 | ProHoster\" \/>\n\t\t<meta property=\"og:description\" content=\"\u041a\u043e\u043c\u043f\u0430\u043d\u0438\u044f Qualys \u0432\u044b\u044f\u0432\u0438\u043b\u0430 \u043e\u043f\u0430\u0441\u043d\u0443\u044e \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c (CVE-2023-4911) \u0432 \u043a\u043e\u043c\u043f\u043e\u043d\u043e\u0432\u0449\u0438\u043a\u0435 ld.so, \u043f\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u043c\u043e\u043c \u0432 \u0441\u043e\u0441\u0442\u0430\u0432\u0435 \u0441\u0438\u0441\u0442\u0435\u043c\u043d\u043e\u0439 \u0421\u0438-\u0431\u0438\u0431\u043b\u0438\u043e\u0442\u0435\u043a\u0438 Glibc (GNU libc).\" \/>\n\t\t<meta property=\"og:url\" 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umo\u017e\u0148uj\u00faca z\u00edska\u0165 pr\u00e1va root v syst\u00e9me | ProHoster","description":"Spolo\u010dnos\u0165 Qualys odhalila nebezpe\u010dn\u00fa zranite\u013enos\u0165 (CVE-2023-4911) v linkova\u010di ld.so, dod\u00e1vanom v r\u00e1mci syst\u00e9movej C si kni\u017enice Glibc (GNU libc).","canonical_url":"https:\/\/prohoster.info\/sk\/blog\/news\/uyazvimost-v-glibc-ld-so-pozvolyayushhaya-poluchit-prava-root-v-sisteme","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\udd47\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u0432 Glibc ld.so, \u043f\u043e\u0437\u0432\u043e\u043b\u044f\u044e\u0449\u0430\u044f \u043f\u043e\u043b\u0443\u0447\u0438\u0442\u044c \u043f\u0440\u0430\u0432\u0430 root \u0432 \u0441\u0438\u0441\u0442\u0435\u043c\u0435 | ProHoster","og:description":"\u041a\u043e\u043c\u043f\u0430\u043d\u0438\u044f Qualys \u0432\u044b\u044f\u0432\u0438\u043b\u0430 \u043e\u043f\u0430\u0441\u043d\u0443\u044e \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c (CVE-2023-4911) \u0432 \u043a\u043e\u043c\u043f\u043e\u043d\u043e\u0432\u0449\u0438\u043a\u0435 ld.so, \u043f\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u043c\u043e\u043c \u0432 \u0441\u043e\u0441\u0442\u0430\u0432\u0435 \u0441\u0438\u0441\u0442\u0435\u043c\u043d\u043e\u0439 \u0421\u0438-\u0431\u0438\u0431\u043b\u0438\u043e\u0442\u0435\u043a\u0438 Glibc (GNU libc).","og:url":"https:\/\/prohoster.info\/sk\/blog\/news\/uyazvimost-v-glibc-ld-so-pozvolyayushhaya-poluchit-prava-root-v-sisteme","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":"2023-10-04T06:10:45+00:00","article:modified_time":"2023-10-04T06:10:45+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\/110411","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\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/prohoster.info\/sk\/wp-json\/wp\/v2\/comments?post=110411"}],"version-history":[{"count":0,"href":"https:\/\/prohoster.info\/sk\/wp-json\/wp\/v2\/posts\/110411\/revisions"}],"wp:attachment":[{"href":"https:\/\/prohoster.info\/sk\/wp-json\/wp\/v2\/media?parent=110411"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/prohoster.info\/sk\/wp-json\/wp\/v2\/categories?post=110411"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/prohoster.info\/sk\/wp-json\/wp\/v2\/tags?post=110411"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}