{"id":35693,"date":"2019-10-31T22:05:48","date_gmt":"2019-10-31T19:05:48","guid":{"rendered":"https:\/\/prohoster.info\/blog\/uyazvimost-v-amd-sev-pozvolyayushhaya-opredelit-klyuchi-shifrovaniya\/"},"modified":"2019-10-31T22:05:48","modified_gmt":"2019-10-31T19:05:48","slug":"uyazvimost-v-amd-sev-pozvolyayushhaya-opredelit-klyuchi-shifrovaniya","status":"publish","type":"post","link":"https:\/\/prohoster.info\/pt\/blog\/news\/uyazvimost-v-amd-sev-pozvolyayushhaya-opredelit-klyuchi-shifrovaniya","title":{"rendered":"Vulnerability in AMD SEV that allows identifying encryption keys","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"

Desenvolvedores da equipe Google Cloud identificaram<\/a><\/noindex> uma vulnerabilidade (CVE-2019-9836) na implementa\u00e7\u00e3o da tecnologia AMD SEV (Secure Encrypted Virtualization), que permite comprometer dados protegidos por essa tecnologia. O AMD SEV garante criptografia transparente da mem\u00f3ria das m\u00e1quinas virtuais em n\u00edvel de hardware, onde o acesso aos dados descriptografados \u00e9 apenas da atual m\u00e1quina virtual, enquanto as outras m\u00e1quinas virtuais e o hypervisor, ao tentarem acessar essa mem\u00f3ria, recebem um conjunto de dados criptografados.<\/p>\n

O problema identificado permite a recupera\u00e7\u00e3o completa do conte\u00fado da chave PDH fechada, processada no n\u00edvel de um processador seguro PSP (AMD Security Processor), que n\u00e3o est\u00e1 acess\u00edvel para o sistema operacional principal.
\nCom a chave PDH, o atacante pode ent\u00e3o recuperar a chave de sess\u00e3o e a sequ\u00eancia secreta definida na cria\u00e7\u00e3o da m\u00e1quina virtual, obtendo acesso aos dados criptografados. <\/p>\n

A vulnerabilidade \u00e9 causada por falhas na implementa\u00e7\u00e3o de curvas el\u00edpticas (ECC) utilizadas para criptografia, que permitem realizar um ataque<\/a><\/noindex> para a recupera\u00e7\u00e3o dos par\u00e2metros da curva. Durante a execu\u00e7\u00e3o do comando para iniciar uma m\u00e1quina virtual protegida, o atacante pode enviar par\u00e2metros da curva que n\u00e3o correspondem aos par\u00e2metros recomendados pelo NIST, levando ao uso de valores de ponto de ordem baixa em opera\u00e7\u00f5es de multiplica\u00e7\u00e3o com dados da chave fechada. <\/p>\n

A seguran\u00e7a do protocolo ECDH depende diretamente da ordem<\/a><\/noindex> de do ponto inicial gerado da curva, cujo logaritmo discreto representa uma tarefa muito complexa. Em um dos passos de inicializa\u00e7\u00e3o do ambiente AMD SEV, nos c\u00e1lculos com a chave fechada, s\u00e3o utilizados par\u00e2metros fornecidos pelo usu\u00e1rio. Na ess\u00eancia, realiza-se uma opera\u00e7\u00e3o de multiplica\u00e7\u00e3o de dois pontos, sendo que um deles corresponde \u00e0 chave fechada. Se o segundo ponto se relacionar a n\u00fameros primos de baixa ordem, o atacante pode determinar os par\u00e2metros do primeiro ponto (bits do m\u00f3dulo utilizado na opera\u00e7\u00e3o de exponencia\u00e7\u00e3o modular) atrav\u00e9s da tentativa de todos os valores poss\u00edveis. Para determinar a chave fechada, os fragmentos adequados de n\u00fameros primos podem ent\u00e3o ser reunidos atrav\u00e9s da<\/a><\/noindex> Teorema Chin\u00eas dos Restos Os servidores da plataforma AMD EPYC, que utilizam firmwares SEV at\u00e9 a vers\u00e3o 0.17 build 11, est\u00e3o vulner\u00e1veis. A empresa AMD j\u00e1<\/a><\/noindex>.<\/p>\n

toma medidas para corrigir publicou<\/noindex> Atualiza\u00e7\u00e3o de firmware que adiciona a restri\u00e7\u00e3o no uso de pontos que n\u00e3o correspondem \u00e0 curva NIST. Ao mesmo tempo, os certificados gerados anteriormente para as chaves PDH permanecem v\u00e1lidos, o que permite que um invasor realize um ataque de migra\u00e7\u00e3o de m\u00e1quinas virtuais de ambientes protegidos contra a vulnerabilidade para ambientes suscet\u00edveis ao problema. Tamb\u00e9m \u00e9 mencionada a possibilidade de um ataque que reverte a vers\u00e3o do firmware para uma vers\u00e3o antiga e vulner\u00e1vel, mas essa possibilidade ainda n\u00e3o foi confirmada.<\/p>\n

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

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

\u0420\u0430\u0437\u0440\u0430\u0431\u043e\u0442\u0447\u0438\u043a\u0438 \u0438\u0437 \u043a\u043e\u043c\u0430\u043d\u0434\u044b Google Cloud \u0432\u044b\u044f\u0432\u0438\u043b\u0438 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c (CVE-2019-9836) \u0432 \u0440\u0435\u0430\u043b\u0438\u0437\u0430\u0446\u0438\u0438 \u0442\u0435\u0445\u043d\u043e\u043b\u043e\u0433\u0438\u0438 AMD SEV (Secure Encrypted Virtualization), \u043f\u043e\u0437\u0432\u043e\u043b\u044f\u044e\u0449\u0443\u044e \u0441\u043a\u043e\u043c\u043f\u0440\u043e\u043c\u0435\u0442\u0438\u0440\u043e\u0432\u0430\u0442\u044c \u0437\u0430\u0449\u0438\u0449\u0451\u043d\u043d\u044b\u0435 \u043f\u0440\u0438 \u043f\u043e\u043c\u043e\u0449\u0438 \u0434\u0430\u043d\u043d\u043e\u0439 \u0442\u0435\u0445\u043d\u043e\u043b\u043e\u0433\u0438\u0438 \u0434\u0430\u043d\u043d\u044b\u0435. AMD SEV \u043d\u0430 \u0430\u043f\u043f\u0430\u0440\u0430\u0442\u043d\u043e\u043c \u0443\u0440\u043e\u0432\u043d\u0435 \u043e\u0431\u0435\u0441\u043f\u0435\u0447\u0438\u0432\u0430\u0435\u0442 \u043f\u0440\u043e\u0437\u0440\u0430\u0447\u043d\u043e\u0435 \u0448\u0438\u0444\u0440\u043e\u0432\u0430\u043d\u0438\u0435 \u043f\u0430\u043c\u044f\u0442\u0438 \u0432\u0438\u0440\u0442\u0443\u0430\u043b\u044c\u043d\u044b\u0445 \u043c\u0430\u0448\u0438\u043d, \u043f\u0440\u0438 \u043a\u043e\u0442\u043e\u0440\u043e\u0439 \u0434\u043e\u0441\u0442\u0443\u043f \u043a \u0440\u0430\u0441\u0448\u0438\u0444\u0440\u043e\u0432\u0430\u043d\u043d\u044b\u043c \u0434\u0430\u043d\u043d\u044b\u043c \u0438\u043c\u0435\u0435\u0442 \u0442\u043e\u043b\u044c\u043a\u043e \u0442\u0435\u043a\u0443\u0449\u0430\u044f \u0433\u043e\u0441\u0442\u0435\u0432\u0430\u044f \u0441\u0438\u0441\u0442\u0435\u043c\u0430, \u0430 \u043e\u0441\u0442\u0430\u043b\u044c\u043d\u044b\u0435 \u0432\u0438\u0440\u0442\u0443\u0430\u043b\u044c\u043d\u044b\u0435 \u043c\u0430\u0448\u0438\u043d\u044b \u0438 \u0433\u0438\u043f\u0435\u0440\u0432\u0438\u0437\u043e\u0440 \u043f\u0440\u0438 \u043f\u043e\u043f\u044b\u0442\u043a\u0435 \u043e\u0431\u0440\u0430\u0449\u0435\u043d\u0438\u044f […]<\/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-35693","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\udd47Vulnerabilidade no AMD SEV que permite determinar chaves de criptografia | ProHoster","description":"Desenvolvedores da equipe do Google Cloud identificaram uma vulnerabilidade (CVE-2019-9836) na implementa\u00e7\u00e3o da tecnologia AMD SEV (Secure).","canonical_url":"https:\/\/prohoster.info\/pt\/blog\/news\/uyazvimost-v-amd-sev-pozvolyayushhaya-opredelit-klyuchi-shifrovaniya","robots":"max-image-preview:large","keywords":"","webmasterTools":{"miscellaneous":""},"schema":null,"og:locale":"pt_PT","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 AMD SEV, \u043f\u043e\u0437\u0432\u043e\u043b\u044f\u044e\u0449\u0430\u044f \u043e\u043f\u0440\u0435\u0434\u0435\u043b\u0438\u0442\u044c \u043a\u043b\u044e\u0447\u0438 \u0448\u0438\u0444\u0440\u043e\u0432\u0430\u043d\u0438\u044f | ProHoster","og:description":"\u0420\u0430\u0437\u0440\u0430\u0431\u043e\u0442\u0447\u0438\u043a\u0438 \u0438\u0437 \u043a\u043e\u043c\u0430\u043d\u0434\u044b Google Cloud \u0432\u044b\u044f\u0432\u0438\u043b\u0438 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c (CVE-2019-9836) \u0432 \u0440\u0435\u0430\u043b\u0438\u0437\u0430\u0446\u0438\u0438 \u0442\u0435\u0445\u043d\u043e\u043b\u043e\u0433\u0438\u0438 AMD SEV (Secure.","og:url":"https:\/\/prohoster.info\/pt\/blog\/news\/uyazvimost-v-amd-sev-pozvolyayushhaya-opredelit-klyuchi-shifrovaniya","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":"2019-10-31T19:05:48+00:00","article:modified_time":"2019-10-31T19:05:48+00:00","article:publisher":"https:\/\/www.facebook.com\/prohoster","article:author":"https:\/\/www.facebook.com\/prohoster"},"aioseo_meta_data":{"post_id":"35693","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":"2026-01-22 00:24:19","breadcrumb_settings":null,"limit_modified_date":false,"reviewed_by":null,"ai":null,"created":"2021-03-01 01:57:46","updated":"2026-01-22 00:24:19","focus_keyword":null,"additional_keywords":null,"truseo_locale":null},"gt_translate_keys":[{"key":"link","format":"url"}],"_links":{"self":[{"href":"https:\/\/prohoster.info\/pt\/wp-json\/wp\/v2\/posts\/35693","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/prohoster.info\/pt\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/prohoster.info\/pt\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/prohoster.info\/pt\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/prohoster.info\/pt\/wp-json\/wp\/v2\/comments?post=35693"}],"version-history":[{"count":0,"href":"https:\/\/prohoster.info\/pt\/wp-json\/wp\/v2\/posts\/35693\/revisions"}],"wp:attachment":[{"href":"https:\/\/prohoster.info\/pt\/wp-json\/wp\/v2\/media?parent=35693"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/prohoster.info\/pt\/wp-json\/wp\/v2\/categories?post=35693"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/prohoster.info\/pt\/wp-json\/wp\/v2\/tags?post=35693"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}