{"id":41110,"date":"2020-02-05T21:30:57","date_gmt":"2020-02-05T18:30:57","guid":{"rendered":"https:\/\/prohoster.info\/blog\/blog_prohoster\/metody-otklyucheniya-zashhity-lockdown-v-ubuntu-dlya-udalyonnogo-obhoda-uefi-secure-boot"},"modified":"2020-02-05T21:30:57","modified_gmt":"2020-02-05T18:30:57","slug":"metody-otklyucheniya-zashhity-lockdown-v-ubuntu-dlya-udalyonnogo-obhoda-uefi-secure-boot","status":"publish","type":"post","link":"https:\/\/prohoster.info\/it\/blog\/metody-otklyucheniya-zashhity-lockdown-v-ubuntu-dlya-udalyonnogo-obhoda-uefi-secure-boot","title":{"rendered":"Metodi per disattivare la protezione Lockdown in Ubuntu per bypassare UEFI Secure Boot","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"

Andrej Konovalov di Google ha pubblicato<\/a><\/noindex> metodo di disattivazione remota della protezione Lockdown<\/a><\/noindex>, proposto nel pacchetto con il kernel Linux fornito in Ubuntu (metodi teoricamente proposti devono<\/a><\/noindex> funzionare con il kernel di Fedora e altri distribuzioni, ma non sono stati testati). <\/p>\n

Lockdown limita l'accesso dell'utente root al kernel e blocca i percorsi di bypass di UEFI Secure Boot. Ad esempio, in modalit\u00e0 lockdown, l'accesso a \/dev\/mem, \/dev\/kmem, \/dev\/port, \/proc\/kcore, debugfs, modalit\u00e0 di debug kprobes, mmiotrace, tracefs, BPF, PCMCIA CIS (Card Information Structure), alcune interfacce ACPI e registri MSR della CPU \u00e8 limitato; le chiamate kexec_file e kexec_load sono bloccate, il passaggio in modalit\u00e0 sleep \u00e8 vietato, l'uso di DMA per dispositivi PCI \u00e8 limitato, l'importazione di codice ACPI da variabili EFI \u00e8 vietata, e non sono consentite manipolazioni con porte di input\/output, inclusa la modifica del numero di interruzioni e della porta di input\/output per la porta seriale.<\/p>\n

Il meccanismo Lockdown \u00e8 stato recentemente aggiunto al kernel Linux. 5.4<\/a><\/noindex>, ma nei kernel forniti nelle distribuzioni \u00e8 ancora implementato sotto forma di patch o arricchito con patch. Una delle differenze tra i moduli forniti nelle distribuzioni e l'implementazione integrata nel kernel \u00e8 la possibilit\u00e0 di disattivare il blocco fornito in presenza di accesso fisico al sistema. <\/p>\n

In Ubuntu e Fedora, per disattivare il Lockdown \u00e8 prevista la combinazione di tasti Alt+SysRq+X. Si presume che la combinazione Alt+SysRq+X possa essere utilizzata solo con accesso fisico al dispositivo, mentre in caso di attacco remoto e ottenimento dell'accesso root, l'attaccante non potr\u00e0 disattivare il Lockdown e, ad esempio, caricare un modulo con rootkit nel kernel senza firma digitale. <\/p>\n

Andrey Konovalov ha dimostrato che i metodi di conferma della presenza fisica dell'utente legati all'uso della tastiera non sono efficaci. Il modo pi\u00f9 semplice per disattivare il Lockdown sarebbe una simulazione software della pressione di Alt+SysRq+X tramite \/dev\/uinput, ma questa opzione \u00e8 inizialmente bloccata. Tuttavia, sono stati identificati almeno altri due modi per sostituire Alt+SysRq+X.<\/a><\/noindex> la pressione di Alt+SysRq+X tramite \/dev\/uinput \u00e8 inizialmente bloccata. Sono stati identificati almeno altri due metodi per inserire Alt+SysRq+X. <\/p>\n

\u041f\u0435\u0440\u0432\u044b\u0439 \u0441\u043f\u043e\u0441\u043e\u0431 \u0441\u0432\u044f\u0437\u0430\u043d \u0441 \u0438\u0441\u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u043d\u0438\u0435\u043c \u0438\u043d\u0442\u0435\u0440\u0444\u0435\u0439\u0441\u0430 «sysrq-trigger» — \u0434\u043b\u044f \u0441\u0438\u043c\u0443\u043b\u044f\u0446\u0438\u0438 \u0434\u043e\u0441\u0442\u0430\u0442\u043e\u0447\u043d\u043e \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u044c \u044d\u0442\u043e\u0442 \u0438\u043d\u0442\u0435\u0440\u0444\u0435\u0439\u0441, \u0437\u0430\u043f\u0438\u0441\u0430\u0432 «1» \u0432 \/proc\/sys\/kernel\/sysrq, \u0430 \u0437\u0430\u0442\u0435\u043c \u0437\u0430\u043f\u0438\u0441\u0430\u0442\u044c «x» \u0432 \/proc\/sysrq-trigger. \u0423\u043a\u0430\u0437\u0430\u043d\u043d\u0430\u044f \u043b\u0430\u0437\u0435\u0439\u043a\u0430 risolto<\/a><\/noindex> \u00e8 stata introdotta nell'aggiornamento del kernel di dicembre per Ubuntu e in Fedora 31. \u00c8 interessante notare che gli sviluppatori, come nel caso di \/dev\/uinput, inizialmente hanno cercato<\/a><\/noindex> di bloccare questo metodo, ma il blocco non ha funzionato a causa di un errore<\/a><\/noindex> nel codice.<\/p>\n

Il secondo metodo consiste nell'emulare una tastiera tramite USB\/IP<\/a><\/noindex> e nell'inviare successivamente la sequenza Alt+SysRq+X tramite la tastiera virtuale. Nel kernel di Ubuntu fornito, USB\/IP \u00e8 abilitato di default (CONFIG_USBIP_VHCI_HCD=m e CONFIG_USBIP_CORE=m) e sono forniti i moduli necessari firmati digitalmente usbip_core e vhci_hcd. Un attaccante pu\u00f2 creare<\/a><\/noindex> creare un dispositivo USB virtuale, avviando<\/a><\/noindex> un gestore di rete sull'interfaccia loopback e collegandolo come dispositivo USB remoto tramite USB\/IP. Questo metodo \u00e8 stato segnalato<\/a><\/noindex> agli sviluppatori di Ubuntu, ma la correzione non \u00e8 ancora stata rilasciata.<\/p>\n

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

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

\u0410\u043d\u0434\u0440\u0435\u0439 \u041a\u043e\u043d\u043e\u0432\u0430\u043b\u043e\u0432 \u0438\u0437 \u043a\u043e\u043c\u043f\u0430\u043d\u0438\u0438 Google \u043e\u043f\u0443\u0431\u043b\u0438\u043a\u043e\u0432\u0430\u043b \u0441\u043f\u043e\u0441\u043e\u0431 \u0443\u0434\u0430\u043b\u0451\u043d\u043d\u043e\u0433\u043e \u043e\u0442\u043a\u043b\u044e\u0447\u0435\u043d\u0438\u044f \u0437\u0430\u0449\u0438\u0442\u044b Lockdown, \u043f\u0440\u0435\u0434\u043b\u0430\u0433\u0430\u0435\u043c\u043e\u0439 \u0432 \u043f\u0430\u043a\u0435\u0442\u0435 \u0441 \u044f\u0434\u0440\u043e\u043c Linux, \u043f\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u043c\u043e\u043c \u0432 Ubuntu (\u0442\u0435\u043e\u0440\u0435\u0442\u0438\u0447\u0435\u0441\u043a\u0438 \u043f\u0440\u0435\u0434\u043b\u043e\u0436\u0435\u043d\u043d\u044b\u0435 \u043c\u0435\u0442\u043e\u0434\u044b \u0434\u043e\u043b\u0436\u043d\u044b \u0440\u0430\u0431\u043e\u0442\u0430\u0442\u044c \u0441 \u044f\u0434\u0440\u043e\u043c Fedora \u0438 \u0434\u0440\u0443\u0433\u0438\u0445 \u0434\u0438\u0441\u0442\u0440\u0438\u0431\u0443\u0442\u0438\u0432\u043e\u0432, \u043d\u043e \u043e\u043d\u0438 \u043d\u0435 \u043f\u0440\u043e\u0442\u0435\u0441\u0442\u0438\u0440\u043e\u0432\u0430\u043d\u044b). Lockdown \u043e\u0433\u0440\u0430\u043d\u0438\u0447\u0438\u0432\u0430\u0435\u0442 \u0434\u043e\u0441\u0442\u0443\u043f \u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u0442\u0435\u043b\u044f root \u043a \u044f\u0434\u0440\u0443 \u0438 \u0431\u043b\u043e\u043a\u0438\u0440\u0443\u0435\u0442 \u043f\u0443\u0442\u0438 \u043e\u0431\u0445\u043e\u0434\u0430 UEFI Secure Boot. \u041d\u0430\u043f\u0440\u0438\u043c\u0435\u0440, \u0432 \u0440\u0435\u0436\u0438\u043c\u0435 lockdown \u043e\u0433\u0440\u0430\u043d\u0438\u0447\u0438\u0432\u0430\u0435\u0442\u0441\u044f \u0434\u043e\u0441\u0442\u0443\u043f […]<\/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":[],"tags":[],"class_list":["post-41110","post","type-post","status-publish","format-standard","hentry"],"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\udd47Metodi per disattivare la protezione Lockdown in Ubuntu per il bypass remoto del UEFI Secure Boot | ProHoster","description":"Andrei Konovalov di Google ha pubblicato un metodo per disattivare a distanza la protezione Lockdown, inclusa nel pacchetto con il kernel Linux fornito in Ubuntu (in teoria, i metodi proposti dovrebbero funzionare anche con il kernel di Fedora e di altre distribuzioni, ma non sono stati testati). Lockdown limita l'accesso dell'utente root al kernel e blocca i percorsi di bypass del UEFI Secure Boot. Ad esempio, in modalit\u00e0 lockdown, l'accesso \u00e8 limitato.","canonical_url":"https:\/\/prohoster.info\/it\/blog\/metody-otklyucheniya-zashhity-lockdown-v-ubuntu-dlya-udalyonnogo-obhoda-uefi-secure-boot","robots":"max-image-preview:large","keywords":"","webmasterTools":{"miscellaneous":""},"schema":null,"og:locale":"it_IT","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\u041c\u0435\u0442\u043e\u0434\u044b \u043e\u0442\u043a\u043b\u044e\u0447\u0435\u043d\u0438\u044f \u0437\u0430\u0449\u0438\u0442\u044b Lockdown \u0432 Ubuntu \u0434\u043b\u044f \u0443\u0434\u0430\u043b\u0451\u043d\u043d\u043e\u0433\u043e \u043e\u0431\u0445\u043e\u0434\u0430 UEFI Secure Boot | ProHoster","og:description":"\u0410\u043d\u0434\u0440\u0435\u0439 \u041a\u043e\u043d\u043e\u0432\u0430\u043b\u043e\u0432 \u0438\u0437 \u043a\u043e\u043c\u043f\u0430\u043d\u0438\u0438 Google \u043e\u043f\u0443\u0431\u043b\u0438\u043a\u043e\u0432\u0430\u043b \u0441\u043f\u043e\u0441\u043e\u0431 \u0443\u0434\u0430\u043b\u0451\u043d\u043d\u043e\u0433\u043e \u043e\u0442\u043a\u043b\u044e\u0447\u0435\u043d\u0438\u044f \u0437\u0430\u0449\u0438\u0442\u044b Lockdown, \u043f\u0440\u0435\u0434\u043b\u0430\u0433\u0430\u0435\u043c\u043e\u0439 \u0432 \u043f\u0430\u043a\u0435\u0442\u0435 \u0441 \u044f\u0434\u0440\u043e\u043c Linux, \u043f\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u043c\u043e\u043c \u0432 Ubuntu (\u0442\u0435\u043e\u0440\u0435\u0442\u0438\u0447\u0435\u0441\u043a\u0438 \u043f\u0440\u0435\u0434\u043b\u043e\u0436\u0435\u043d\u043d\u044b\u0435 \u043c\u0435\u0442\u043e\u0434\u044b \u0434\u043e\u043b\u0436\u043d\u044b \u0440\u0430\u0431\u043e\u0442\u0430\u0442\u044c \u0441 \u044f\u0434\u0440\u043e\u043c Fedora \u0438 \u0434\u0440\u0443\u0433\u0438\u0445 \u0434\u0438\u0441\u0442\u0440\u0438\u0431\u0443\u0442\u0438\u0432\u043e\u0432, \u043d\u043e \u043e\u043d\u0438 \u043d\u0435 \u043f\u0440\u043e\u0442\u0435\u0441\u0442\u0438\u0440\u043e\u0432\u0430\u043d\u044b). Lockdown \u043e\u0433\u0440\u0430\u043d\u0438\u0447\u0438\u0432\u0430\u0435\u0442 \u0434\u043e\u0441\u0442\u0443\u043f \u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u0442\u0435\u043b\u044f root \u043a \u044f\u0434\u0440\u0443 \u0438 \u0431\u043b\u043e\u043a\u0438\u0440\u0443\u0435\u0442 \u043f\u0443\u0442\u0438 \u043e\u0431\u0445\u043e\u0434\u0430 UEFI Secure Boot. \u041d\u0430\u043f\u0440\u0438\u043c\u0435\u0440, \u0432 \u0440\u0435\u0436\u0438\u043c\u0435 lockdown \u043e\u0433\u0440\u0430\u043d\u0438\u0447\u0438\u0432\u0430\u0435\u0442\u0441\u044f \u0434\u043e\u0441\u0442\u0443\u043f","og:url":"https:\/\/prohoster.info\/it\/blog\/metody-otklyucheniya-zashhity-lockdown-v-ubuntu-dlya-udalyonnogo-obhoda-uefi-secure-boot","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":"2020-02-05T18:30:57+00:00","article:modified_time":"2020-02-05T18:30:57+00:00","article:publisher":"https:\/\/www.facebook.com\/prohoster","article:author":"https:\/\/www.facebook.com\/prohoster"},"aioseo_meta_data":{"post_id":"41110","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 10:48:15","updated":"2022-09-28 13:36:48"},"gt_translate_keys":[{"key":"link","format":"url"}],"_links":{"self":[{"href":"https:\/\/prohoster.info\/it\/wp-json\/wp\/v2\/posts\/41110","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/prohoster.info\/it\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/prohoster.info\/it\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/prohoster.info\/it\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/prohoster.info\/it\/wp-json\/wp\/v2\/comments?post=41110"}],"version-history":[{"count":0,"href":"https:\/\/prohoster.info\/it\/wp-json\/wp\/v2\/posts\/41110\/revisions"}],"wp:attachment":[{"href":"https:\/\/prohoster.info\/it\/wp-json\/wp\/v2\/media?parent=41110"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/prohoster.info\/it\/wp-json\/wp\/v2\/categories?post=41110"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/prohoster.info\/it\/wp-json\/wp\/v2\/tags?post=41110"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}