Foram reveladas informa\u00e7\u00f5es sobre a vulnerabilidade CVE-2023-6200 no stack de rede do kernel Linux, que, em determinadas circunst\u00e2ncias, permite que um invasor na rede local execute seu c\u00f3digo ao enviar um pacote ICMPv6 especialmente formatado com uma mensagem RA (Router Advertisement), destinada a anunciar informa\u00e7\u00f5es sobre o roteador. <\/p>\n
A vulnerabilidade s\u00f3 pode ser explorada a partir da rede local e se manifesta em sistemas com suporte IPv6 ativado e um par\u00e2metro sysctl ativo chamado \u201cnet.ipv6.conf..accept_ra\u201d (pode ser verificado com o comando \u201csysctl net.ipv6.conf | grep accept_ra\u201d), que por padr\u00e3o est\u00e1 desativado no RHEL e Ubuntu para interfaces de rede externas, mas ativado para a interface loopback, permitindo um ataque a partir do mesmo sistema. <\/p>\n
A vulnerabilidade \u00e9 causada por uma condi\u00e7\u00e3o de corrida na manipula\u00e7\u00e3o do coletor de lixo de entradas obsoletas fib6_info, o que pode levar a um acesso a uma \u00e1rea de mem\u00f3ria j\u00e1 liberada (use-after-free). Ao receber um pacote ICMPv6 com uma mensagem de an\u00fancio de roteador (RA, Router Advertisement), o stack de rede chama a fun\u00e7\u00e3o ndisc_router_discovery(), que, se os dados de tempo de vida da rota estiverem presentes na mensagem RA, chama a fun\u00e7\u00e3o fib6_set_expires() e preenche a estrutura gc_link. Para limpar entradas obsoletas, \u00e9 utilizada a fun\u00e7\u00e3o fib6_clean_expires(), que desanexa a entrada em gc_link e limpa a mem\u00f3ria utilizada pela estrutura fib6_info. H\u00e1 um momento espec\u00edfico em que a mem\u00f3ria para a estrutura fib6_info j\u00e1 foi liberada, mas a refer\u00eancia a ela continua na estrutura gc_link. <\/p>\n
A vulnerabilidade aparece a partir da vers\u00e3o 6.6 e foi corrigida nas vers\u00f5es 6.6.9 e 6.7. O status da corre\u00e7\u00e3o da vulnerabilidade em distribui\u00e7\u00f5es pode ser avaliado nas seguintes p\u00e1ginas: Debian, Ubuntu, SUSE, RHEL, Fedora, Arch Linux, Gentoo, Slackware. Entre as distribui\u00e7\u00f5es que fornecem pacotes com o kernel 6.6, podemos mencionar Arch Linux, Gentoo, Fedora, Slackware, OpenMandriva e Manjaro; nas demais distribui\u00e7\u00f5es, pode ocorrer a retrocompatibilidade com erros em pacotes com vers\u00f5es de kernel mais antigas (por exemplo, no Debian, menciona-se que o pacote com o kernel 6.5.13 \u00e9 vulner\u00e1vel, enquanto a altera\u00e7\u00e3o problem\u00e1tica apareceu na vers\u00e3o 6.6). Como uma solu\u00e7\u00e3o alternativa de prote\u00e7\u00e3o, \u00e9 poss\u00edvel desativar o IPv6 ou atribuir o valor 0 aos par\u00e2metros \u201cnet.ipv6.conf.*.accept_ra\u201d. \u0420\u0430\u0441\u043a\u0440\u044b\u0442\u0430 \u0438\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u044f \u043e\u0431 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438 CVE-2023-6200) \u0432 \u0441\u0435\u0442\u0435\u0432\u043e\u043c \u0441\u0442\u0435\u043a\u0435 \u044f\u0434\u0440\u0430 Linux, \u043a\u043e\u0442\u043e\u0440\u0430\u044f \u043f\u0440\u0438 \u043e\u043f\u0440\u0435\u0434\u0435\u043b\u0451\u043d\u043d\u044b\u0445 \u043e\u0431\u0441\u0442\u043e\u044f\u0442\u0435\u043b\u044c\u0441\u0442\u0432\u0430\u0445 \u043f\u043e\u0437\u0432\u043e\u043b\u044f\u0435\u0442 \u0437\u043b\u043e\u0443\u043c\u044b\u0448\u043b\u0435\u043d\u043d\u0438\u043a\u0443 \u0438\u0437 \u043b\u043e\u043a\u0430\u043b\u044c\u043d\u043e\u0439 \u0441\u0435\u0442\u0438 \u0434\u043e\u0431\u0438\u0442\u044c\u0441\u044f \u0432\u044b\u043f\u043e\u043b\u043d\u0435\u043d\u0438\u044f \u0441\u0432\u043e\u0435\u0433\u043e \u043a\u043e\u0434\u0430 \u0447\u0435\u0440\u0435\u0437 \u043e\u0442\u043f\u0440\u0430\u0432\u043a\u0443 \u0441\u043f\u0435\u0446\u0438\u0430\u043b\u044c\u043d\u043e \u043e\u0444\u043e\u0440\u043c\u043b\u0435\u043d\u043d\u043e\u0433\u043e \u043f\u0430\u043a\u0435\u0442\u0430 ICMPv6 \u0441 \u0441\u043e\u043e\u0431\u0449\u0435\u043d\u0438\u0435\u043c RA (Router Advertisement), \u043f\u0440\u0435\u0434\u043d\u0430\u0437\u043d\u0430\u0447\u0435\u043d\u043d\u044b\u043c \u0434\u043b\u044f \u0430\u043d\u043e\u043d\u0441\u0438\u0440\u043e\u0432\u0430\u043d\u0438\u044f \u0438\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u0438 \u043e \u043c\u0430\u0440\u0448\u0440\u0443\u0442\u0438\u0437\u0430\u0442\u043e\u0440\u0435. \u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u043c\u043e\u0436\u0435\u0442 \u0431\u044b\u0442\u044c \u044d\u043a\u0441\u043f\u043b\u0443\u0430\u0442\u0438\u0440\u043e\u0432\u0430\u043d\u0430 \u0442\u043e\u043b\u044c\u043a\u043e \u0438\u0437 \u043b\u043e\u043a\u0430\u043b\u044c\u043d\u043e\u0439 \u0441\u0435\u0442\u0438 \u0438 \u043f\u0440\u043e\u044f\u0432\u043b\u044f\u0435\u0442\u0441\u044f \u0432 \u0441\u0438\u0441\u0442\u0435\u043c\u0430\u0445 \u0441\u043e \u0432\u043a\u043b\u044e\u0447\u0451\u043d\u043d\u043e\u0439 \u043f\u043e\u0434\u0434\u0435\u0440\u0436\u043a\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-113232","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\udd47 Vulnerabilidade no stack IPv6 do n\u00facleo Linux permite execu\u00e7\u00e3o remota de c\u00f3digo | ProHoster","description":"Foi revelada informa\u00e7\u00e3o sobre a vulnerabilidade CVE-2023-6200 no stack de rede do n\u00facleo Linux, que em determinadas circunst\u00e2ncias permite que um invasor na rede local consiga executar seu c\u00f3digo atrav\u00e9s do 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ProHoster","og:description":"\u0420\u0430\u0441\u043a\u0440\u044b\u0442\u0430 \u0438\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u044f \u043e\u0431 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438 CVE-2023-6200) \u0432 \u0441\u0435\u0442\u0435\u0432\u043e\u043c \u0441\u0442\u0435\u043a\u0435 \u044f\u0434\u0440\u0430 Linux, \u043a\u043e\u0442\u043e\u0440\u0430\u044f \u043f\u0440\u0438 \u043e\u043f\u0440\u0435\u0434\u0435\u043b\u0451\u043d\u043d\u044b\u0445 \u043e\u0431\u0441\u0442\u043e\u044f\u0442\u0435\u043b\u044c\u0441\u0442\u0432\u0430\u0445 \u043f\u043e\u0437\u0432\u043e\u043b\u044f\u0435\u0442 \u0437\u043b\u043e\u0443\u043c\u044b\u0448\u043b\u0435\u043d\u043d\u0438\u043a\u0443 \u0438\u0437 \u043b\u043e\u043a\u0430\u043b\u044c\u043d\u043e\u0439 \u0441\u0435\u0442\u0438 \u0434\u043e\u0431\u0438\u0442\u044c\u0441\u044f \u0432\u044b\u043f\u043e\u043b\u043d\u0435\u043d\u0438\u044f \u0441\u0432\u043e\u0435\u0433\u043e \u043a\u043e\u0434\u0430 \u0447\u0435\u0440\u0435\u0437 \u043e\u0442\u043f\u0440\u0430\u0432\u043a\u0443.","og:url":"https:\/\/prohoster.info\/pt\/blog\/news\/uyazvimost-v-ipv6-steke-yadra-linux-dopuskayushhaya-udalyonnoe-vypolnenie-koda","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":"2024-01-29T16:50:31+00:00","article:modified_time":"2024-01-29T16:50:31+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\/pt\/wp-json\/wp\/v2\/posts\/113232","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=113232"}],"version-history":[{"count":0,"href":"https:\/\/prohoster.info\/pt\/wp-json\/wp\/v2\/posts\/113232\/revisions"}],"wp:attachment":[{"href":"https:\/\/prohoster.info\/pt\/wp-json\/wp\/v2\/media?parent=113232"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/prohoster.info\/pt\/wp-json\/wp\/v2\/categories?post=113232"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/prohoster.info\/pt\/wp-json\/wp\/v2\/tags?post=113232"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
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Fonte: opennet.ru<\/a> <\/p>","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":"