{"id":76196,"date":"2020-03-31T19:42:05","date_gmt":"2020-03-31T17:42:05","guid":{"rendered":"https:\/\/prohoster.info\/blog\/novosti-interneta\/uyazvimost-v-yadre-linux-pozvolyayushhaya-povysit-svoi-privilegii-cherez-bpf"},"modified":"2020-03-31T19:42:05","modified_gmt":"2020-03-31T17:42:05","slug":"uyazvimost-v-yadre-linux-pozvolyayushhaya-povysit-svoi-privilegii-cherez-bpf","status":"publish","type":"post","link":"https:\/\/prohoster.info\/ro\/blog\/news\/uyazvimost-v-yadre-linux-pozvolyayushhaya-povysit-svoi-privilegii-cherez-bpf","title":{"rendered":"O vulnerabilitate \u00een nucleul Linux care permite cre\u0219terea privilegiilor prin BPF","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"

Publicate<\/a><\/noindex> informa\u021bii despre vulnerabilitate (CVE-2020-8835<\/a><\/noindex>) \u00een nucleul Linux, care a fost utilizat\u0103 \u00een competi\u021bia Pwn2Own 2020<\/a><\/noindex> \u00een demonstrarea hack-ului Ubuntu. Vulnerabilitatea a permis unui utilizator f\u0103r\u0103 privilegii s\u0103 ob\u021bin\u0103 drepturi de root. Exist\u0103 un exploit func\u021bional, dar acesta nu a fost publicat p\u00e2n\u0103 acum. Vulnerabilitatea se afl\u0103 \u00een subsistemul eBPF, care permite rularea handler-elor pentru trasarea \u0219i analiza func\u021bion\u0103rii subsistemelor \u0219i gestionarea traficului, realizate \u00een interiorul nucleului \u00eentr-o ma\u0219in\u0103 virtual\u0103 special\u0103 cu JIT.<\/p>\n

Problema este cauzat\u0103 de o eroare \u00een func\u021bia __reg_bound_offset32(), folosit\u0103 pentru a verifica opera\u021biunile pe 32 de bi\u021bi \u00een bytecode BPF. Din cauza calculului gre\u0219it al limitelor registrului, \u00een timpul proces\u0103rii aplica\u021biilor BPF special concepute au ap\u0103rut condi\u021bii pentru citirea \u0219i scrierea datelor dincolo de bufferul alocat \u00een zona de memorie a nucleului. Problema a fost introdus\u0103 \u00een nucleul 5.5 \u0219i ulterior, la portarea corecturilor, a fost mutat\u0103 \u00een nucleul 5.4, precum \u0219i \u00een pachetul cu nucleul 5.3<\/a><\/noindex>, oferit \u00een Ubuntu Linux.<\/p>\n

Pentru a bloca vulnerabilitatea, se recomand\u0103 \u00eentoarcerea<\/a><\/noindex> patch-ului problematic sau interzicerea execut\u0103rii aplica\u021biilor BPF de c\u0103tre utilizatorii f\u0103r\u0103 privilegii prin setarea sysctl kernel.unprivileged_bpf_disabled la valoarea 1. Starea corecturilor \u00een distribu\u021bii: Ubuntu<\/a><\/noindex>, Debian<\/a><\/noindex>, Arch<\/a><\/noindex>, Fedora<\/a><\/noindex> \u0219i SUSE<\/a><\/noindex> (\u00een nucleu RHEL<\/a><\/noindex> modificarea problematic\u0103 nu a fost transferat\u0103).<\/p>\n

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

Sursa: opennet.ro<\/a><\/p>","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":"

\u041e\u043f\u0443\u0431\u043b\u0438\u043a\u043e\u0432\u0430\u043d\u044b \u0441\u0432\u0435\u0434\u0435\u043d\u0438\u044f \u043e\u0431 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438 (CVE-2020-8835) \u0432 \u044f\u0434\u0440\u0435 Linux, \u043a\u043e\u0442\u043e\u0440\u0430\u044f \u0431\u044b\u043b\u0430 \u0438\u0441\u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u043d\u0430 \u0432 \u0441\u043e\u0440\u0435\u0432\u043d\u043e\u0432\u0430\u043d\u0438\u0438 Pwn2Own 2020 \u043f\u0440\u0438 \u0434\u0435\u043c\u043e\u043d\u0441\u0442\u0440\u0430\u0446\u0438\u0438 \u0432\u0437\u043b\u043e\u043c\u0430 Ubuntu. \u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u043f\u043e\u0437\u0432\u043e\u043b\u0438\u043b\u0430 \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. \u0420\u0430\u0431\u043e\u0447\u0438\u0439 \u044d\u043a\u0441\u043f\u043b\u043e\u0438\u0442 \u0441\u0443\u0449\u0435\u0441\u0442\u0432\u0443\u0435\u0442, \u043d\u043e \u043f\u043e\u043a\u0430 \u043d\u0435 \u043e\u043f\u0443\u0431\u043b\u0438\u043a\u043e\u0432\u0430\u043d. \u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u043f\u0440\u0438\u0441\u0443\u0442\u0441\u0442\u0432\u0443\u0435\u0442 \u0432 \u043f\u043e\u0434\u0441\u0438\u0441\u0442\u0435\u043c\u0435 eBPF, \u043f\u043e\u0437\u0432\u043e\u043b\u044f\u044e\u0449\u0435\u0439 \u0437\u0430\u043f\u0443\u0441\u043a\u0430\u0442\u044c \u043e\u0431\u0440\u0430\u0431\u043e\u0442\u0447\u0438\u043a\u0438 \u0434\u043b\u044f \u0442\u0440\u0430\u0441\u0441\u0438\u0440\u043e\u0432\u043a\u0438, \u0430\u043d\u0430\u043b\u0438\u0437\u0430 \u0440\u0430\u0431\u043e\u0442\u044b \u043f\u043e\u0434\u0441\u0438\u0441\u0442\u0435\u043c \u0438 \u0443\u043f\u0440\u0430\u0432\u043b\u0435\u043d\u0438\u044f \u0442\u0440\u0430\u0444\u0438\u043a\u043e\u043c, \u0432\u044b\u043f\u043e\u043b\u043d\u044f\u0435\u043c\u044b\u0435 \u0432\u043d\u0443\u0442\u0440\u0438 \u044f\u0434\u0440\u0430 \u0432 \u0441\u043f\u0435\u0446\u0438\u0430\u043b\u044c\u043d\u043e\u0439 \u0432\u0438\u0440\u0442\u0443\u0430\u043b\u044c\u043d\u043e\u0439 […]<\/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-76196","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\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\udd47Vulnerabilitatea din nucleul Linux, care permite cre\u0219terea privilegiilor prin BPF | ProHoster","description":"Au fost publicate informa\u021bii despre vulnerabilitate (","canonical_url":"https:\/\/prohoster.info\/ro\/blog\/news\/uyazvimost-v-yadre-linux-pozvolyayushhaya-povysit-svoi-privilegii-cherez-bpf","robots":"max-image-preview:large","keywords":"","webmasterTools":{"miscellaneous":""},"schema":null,"og:locale":"ro_RO","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 \u044f\u0434\u0440\u0435 Linux, \u043f\u043e\u0437\u0432\u043e\u043b\u044f\u044e\u0449\u0430\u044f \u043f\u043e\u0432\u044b\u0441\u0438\u0442\u044c \u0441\u0432\u043e\u0438 \u043f\u0440\u0438\u0432\u0438\u043b\u0435\u0433\u0438\u0438 \u0447\u0435\u0440\u0435\u0437 BPF | ProHoster","og:description":"\u041e\u043f\u0443\u0431\u043b\u0438\u043a\u043e\u0432\u0430\u043d\u044b \u0441\u0432\u0435\u0434\u0435\u043d\u0438\u044f \u043e\u0431 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438 (","og:url":"https:\/\/prohoster.info\/ro\/blog\/news\/uyazvimost-v-yadre-linux-pozvolyayushhaya-povysit-svoi-privilegii-cherez-bpf","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":"2020-03-31T17:42:05+00:00","article:modified_time":"2020-03-31T17:42:05+00:00","article:publisher":"https:\/\/www.facebook.com\/prohoster","article:author":"https:\/\/www.facebook.com\/prohoster"},"aioseo_meta_data":{"post_id":"76196","title":null,"description":null,"keywords":null,"keyphrases":null,"primary_term":null,"canonical_url":null,"og_title":null,"og_description":null,"og_object_type":"default","og_image_type":"default","og_image_url":null,"og_image_width":null,"og_image_height":null,"og_image_custom_url":null,"og_image_custom_fields":null,"og_video":null,"og_custom_url":null,"og_article_section":null,"og_article_tags":null,"twitter_use_og":false,"twitter_card":"default","twitter_image_type":"default","twitter_image_url":null,"twitter_image_custom_url":null,"twitter_image_custom_fields":null,"twitter_title":null,"twitter_description":null,"schema":{"blockGraphs":[],"customGraphs":[],"default":{"data":{"Article":[],"Course":[],"Dataset":[],"FAQPage":[],"Movie":[],"Person":[],"Product":[],"ProductReview":[],"Car":[],"Recipe":[],"Service":[],"SoftwareApplication":[],"WebPage":[]},"graphName":"","isEnabled":true},"graphs":[]},"schema_type":null,"schema_type_options":null,"pillar_content":false,"robots_default":true,"robots_noindex":false,"robots_noarchive":false,"robots_nosnippet":false,"robots_nofollow":false,"robots_noimageindex":false,"robots_noodp":false,"robots_notranslate":false,"robots_max_snippet":null,"robots_max_videopreview":null,"robots_max_imagepreview":"large","priority":null,"frequency":null,"local_seo":null,"seo_analyzer_scan_date":null,"breadcrumb_settings":null,"limit_modified_date":false,"reviewed_by":null,"ai":null,"created":"2021-02-28 17:41:53","updated":"2022-10-02 19:00:10","focus_keyword":null,"additional_keywords":null,"truseo_locale":null},"gt_translate_keys":[{"key":"link","format":"url"}],"_links":{"self":[{"href":"https:\/\/prohoster.info\/ro\/wp-json\/wp\/v2\/posts\/76196","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/prohoster.info\/ro\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/prohoster.info\/ro\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/prohoster.info\/ro\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/prohoster.info\/ro\/wp-json\/wp\/v2\/comments?post=76196"}],"version-history":[{"count":0,"href":"https:\/\/prohoster.info\/ro\/wp-json\/wp\/v2\/posts\/76196\/revisions"}],"wp:attachment":[{"href":"https:\/\/prohoster.info\/ro\/wp-json\/wp\/v2\/media?parent=76196"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/prohoster.info\/ro\/wp-json\/wp\/v2\/categories?post=76196"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/prohoster.info\/ro\/wp-json\/wp\/v2\/tags?post=76196"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}