{"id":87197,"date":"2020-07-05T07:42:02","date_gmt":"2020-07-05T05:42:02","guid":{"rendered":"https:\/\/prohoster.info\/blog\/novosti-interneta\/uyazvimost-v-ssh-klientah-openssh-i-putty"},"modified":"2020-07-05T07:42:02","modified_gmt":"2020-07-05T05:42:02","slug":"uyazvimost-v-ssh-klientah-openssh-i-putty","status":"publish","type":"post","link":"https:\/\/prohoster.info\/sl\/blog\/news\/uyazvimost-v-ssh-klientah-openssh-i-putty","title":{"rendered":"Vulnerabilnost u SSH klijentima OpenSSH i PuTTY","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"

U SSH klijentima OpenSSH i PuTTY odkrita<\/a><\/noindex> ranljivost<\/a><\/noindex> (CVE-2020-14002<\/a><\/noindex> u PuTTY i CVE-2020-14145<\/a><\/noindex> u OpenSSH), koja dovodi do curenja informacija u algoritmu uskla\u0111ivanja konekcije. Ova ranjivost omogu\u0107ava napada\u010du, koji mo\u017ee presresti klijentov saobra\u0107aj (na primer, kada se korisnik povezuje putem be\u017ei\u010dne pristupne ta\u010dke koju kontroli\u0161e napada\u010d), da utvrdi poku\u0161aj prvobitnog povezivanja klijenta sa hostom, kada klijent jo\u0161 nije sa\u010duvao klju\u010d hosta. <\/p>\n

Saznaju\u0107i da se klijent prvi put povezuje i jo\u0161 nema klju\u010d hosta pohranjen, napada\u010d mo\u017ee preusmeriti vezu kroz sebe (MITM) i dati klijentu svoj klju\u010d hosta, koji \u0107e SSH klijent smatrati klju\u010dem ciljnog hosta, ako ne izvr\u0161i proveru otiska klju\u010da. Tako napada\u010d mo\u017ee organizovati MITM bez izazivanja sumnje kod korisnika i ignorisati sesije u kojima klijent ve\u0107 ima sa\u010duvane klju\u010deve hostova, poku\u0161aj zamene kojih \u0107e rezultirati upozorenjem o promeni klju\u010da hosta. Napad se oslanja na neopreznost korisnika koji ne proveravaju otisak klju\u010da hosta prilikom prvog povezivanja. Oni koji proveravaju otiske klju\u010deva su za\u0161ti\u0107eni od ovakvih napada.<\/p>\n

Kao znak za odre\u0111ivanje prvog poku\u0161aja povezivanja koristi se promena redosleda navedene podr\u017eane algoritme host klju\u010deva. U slu\u010daju da se odvija prvo povezivanje, klijent \u0161alje listu algoritama po defaultu, a ako klju\u010d hosta ve\u0107 postoji u ke\u0161u, tada se povezan algoritam postavlja na prvo mesto (algoritmi se sortiraju po preferencama). <\/p>\n

Problem se manifestuje u izdanjima OpenSSH od 5.7 do 8.3 i u PuTTY od 0.68 do 0.73. Problem ispravljena<\/a><\/noindex> in the release PuTTY 0.74<\/a><\/noindex> dodavanjem opcije za isklju\u010divanje dinami\u010dkog sastavljanja liste algoritama za obradu host klju\u010deva u korist navo\u0111enja algoritama u fiksnom redosledu.<\/p>\n

\u041f\u0440\u043e\u0435\u043a\u0442 OpenSSH \u043d\u0435 \u043f\u043b\u0430\u043d\u0438\u0440\u0443\u0435\u0442 \u0438\u0437\u043c\u0435\u043d\u044f\u0442\u044c \u043f\u043e\u0432\u0435\u0434\u0435\u043d\u0438\u0435 SSH-\u043a\u043b\u0438\u0435\u043d\u0442\u0430, \u0442\u0430\u043a \u043a\u0430\u043a \u0435\u0441\u043b\u0438 \u043d\u0435 \u0443\u043a\u0430\u0437\u0430\u0442\u044c \u0430\u043b\u0433\u043e\u0440\u0438\u0442\u043c \u0438\u043c\u0435\u044e\u0449\u0435\u0433\u043e\u0441\u044f \u043a\u043b\u044e\u0447\u0430 \u043d\u0430 \u043f\u0435\u0440\u0432\u043e\u043c \u043c\u0435\u0441\u0442\u0435, \u0431\u0443\u0434\u0435\u0442 \u043f\u0440\u0438\u043c\u0435\u043d\u0435\u043d\u0430 \u043f\u043e\u043f\u044b\u0442\u043a\u0430 \u043f\u0440\u0438\u043c\u0435\u043d\u0435\u043d\u0438\u044f \u043d\u0435 \u0441\u043e\u043e\u0442\u0432\u0435\u0442\u0441\u0442\u0432\u0443\u044e\u0449\u0435\u0433\u043e \u043f\u0440\u043e\u043a\u044d\u0448\u0438\u0440\u043e\u0432\u0430\u043d\u043d\u043e\u043c\u0443 \u043a\u043b\u044e\u0447\u0443 \u0430\u043b\u0433\u043e\u0440\u0438\u0442\u043c\u0430 \u0441 \u0432\u044b\u0432\u043e\u0434\u043e\u043c \u043f\u0440\u0435\u0434\u0443\u043f\u0440\u0435\u0436\u0434\u0435\u043d\u0438\u044f \u043e \u043d\u0435\u0438\u0437\u0432\u0435\u0441\u0442\u043d\u043e\u043c \u043a\u043b\u044e\u0447\u0435. \u0422.\u0435. \u0432\u043e\u0437\u043d\u0438\u043a\u0430\u0435\u0442 \u0432\u044b\u0431\u043e\u0440 — \u043b\u0438\u0431\u043e \u0443\u0442\u0435\u0447\u043a\u0430 \u0438\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u0438 (OpenSSH \u0438 PuTTY), \u043b\u0438\u0431\u043e \u0432\u044b\u0432\u043e\u0434 \u043f\u0440\u0435\u0434\u0443\u043f\u0440\u0435\u0436\u0434\u0435\u043d\u0438\u0439 \u043e \u0441\u043c\u0435\u043d\u0435 \u043a\u043b\u044e\u0447\u0430 (Dropbear SSH) \u0432 \u0441\u043b\u0443\u0447\u0430\u0435, \u0435\u0441\u043b\u0438 \u0441\u043e\u0445\u0440\u0430\u043d\u0451\u043d\u043d\u044b\u0439 \u043a\u043b\u044e\u0447 \u043d\u0435 \u0441\u043e\u043e\u0442\u0432\u0435\u0442\u0441\u0442\u0432\u0443\u0435\u0442 \u043f\u0435\u0440\u0432\u043e\u043c\u0443 \u0430\u043b\u0433\u043e\u0440\u0438\u0442\u043c\u0443 \u0432 \u0441\u043f\u0438\u0441\u043a\u0435 \u043f\u043e \u0443\u043c\u043e\u043b\u0447\u0430\u043d\u0438\u044e.<\/p>\n

Za zagotovitev za\u0161\u010dite v OpenSSH se priporo\u010da uporaba alternativnih na\u010dinov preverjanja klju\u010da gostitelja s pomo\u010djo zapisov SSHFP v DNSSEC in certifikatov gostitelja (PKI). Prav tako lahko onemogo\u010dite prilagodljivo izbiro algoritmov gostiteljskih klju\u010dev preko mo\u017enosti HostKeyAlgorithms in uporabite mo\u017enost UpdateHostKeys za pridobitev dodatnih gostiteljskih klju\u010dev po avtentikaciji.<\/p>\n

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

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

\u0412 SSH-\u043a\u043b\u0438\u0435\u043d\u0442\u0430\u0445 OpenSSH \u0438 PuTTY \u0432\u044b\u044f\u0432\u043b\u0435\u043d\u0430 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c (CVE-2020-14002 \u0432 PuTTY \u0438 CVE-2020-14145 \u0432 OpenSSH), \u043f\u0440\u0438\u0432\u043e\u0434\u044f\u0449\u0430\u044f \u043a \u0443\u0442\u0435\u0447\u043a\u0435 \u0441\u0432\u0435\u0434\u0435\u043d\u0438\u0439 \u0432 \u0430\u043b\u0433\u043e\u0440\u0438\u0442\u043c\u0435 \u0441\u043e\u0433\u043b\u0430\u0441\u043e\u0432\u0430\u043d\u0438\u044f \u0441\u043e\u0435\u0434\u0438\u043d\u0435\u043d\u0438\u044f. \u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u043f\u043e\u0437\u0432\u043e\u043b\u044f\u0435\u0442 \u0430\u0442\u0430\u043a\u0443\u044e\u0449\u0435\u043c\u0443, \u0441\u043f\u043e\u0441\u043e\u0431\u043d\u043e\u043c\u0443 \u043f\u0435\u0440\u0435\u0445\u0432\u0430\u0442\u0438\u0442\u044c \u0442\u0440\u0430\u0444\u0438\u043a \u043a\u043b\u0438\u0435\u043d\u0442\u0430 (\u043d\u0430\u043f\u0440\u0438\u043c\u0435\u0440, \u043f\u0440\u0438 \u043f\u043e\u0434\u043a\u043b\u044e\u0447\u0435\u043d\u0438\u0438 \u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u0442\u0435\u043b\u044f \u0447\u0435\u0440\u0435\u0437 \u043a\u043e\u043d\u0442\u0440\u043e\u043b\u0438\u0440\u0443\u0435\u043c\u0443\u044e \u0430\u0442\u0430\u043a\u0443\u044e\u0449\u0438\u043c \u0442\u043e\u0447\u043a\u0443 \u0431\u0435\u0441\u043f\u0440\u043e\u0432\u043e\u0434\u043d\u043e\u0433\u043e \u0434\u043e\u0441\u0442\u0443\u043f\u0430), \u043e\u043f\u0440\u0435\u0434\u0435\u043b\u0438\u0442\u044c \u043f\u043e\u043f\u044b\u0442\u043a\u0443 \u043f\u0435\u0440\u0432\u043e\u043d\u0430\u0447\u0430\u043b\u044c\u043d\u043e\u0433\u043e \u043f\u043e\u0434\u043a\u043b\u044e\u0447\u0435\u043d\u0438\u044f \u043a\u043b\u0438\u0435\u043d\u0442\u0430 \u043a \u0445\u043e\u0441\u0442\u0443, \u043a\u043e\u0433\u0434\u0430 \u043a\u043b\u0438\u0435\u043d\u0442\u043e\u043c \u0435\u0449\u0451 \u043d\u0435 \u043f\u0440\u043e\u043a\u044d\u0448\u0438\u0440\u043e\u0432\u0430\u043d \u043a\u043b\u044e\u0447 \u0445\u043e\u0441\u0442\u0430. \u0417\u043d\u0430\u044f, \u0447\u0442\u043e […]<\/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-87197","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\udd47Ranljivost v SSH odjemalcih OpenSSH in PuTTY | ProHoster","description":"U SSH klijentima OpenSSH i PuTTY","canonical_url":"https:\/\/prohoster.info\/sl\/blog\/news\/uyazvimost-v-ssh-klientah-openssh-i-putty","robots":"max-image-preview:large","keywords":"","webmasterTools":{"miscellaneous":""},"schema":null,"og:locale":"sl_SI","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 SSH-\u043a\u043b\u0438\u0435\u043d\u0442\u0430\u0445 OpenSSH \u0438 PuTTY | ProHoster","og:description":"\u0412 SSH-\u043a\u043b\u0438\u0435\u043d\u0442\u0430\u0445 OpenSSH \u0438 PuTTY","og:url":"https:\/\/prohoster.info\/sl\/blog\/news\/uyazvimost-v-ssh-klientah-openssh-i-putty","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":"2020-07-05T05:42:02+00:00","article:modified_time":"2020-07-05T05:42:02+00:00","article:publisher":"https:\/\/www.facebook.com\/prohoster","article:author":"https:\/\/www.facebook.com\/prohoster"},"aioseo_meta_data":{"post_id":"87197","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 13:56:23","updated":"2022-10-07 22:11:57","focus_keyword":null,"additional_keywords":null,"truseo_locale":null},"gt_translate_keys":[{"key":"link","format":"url"}],"_links":{"self":[{"href":"https:\/\/prohoster.info\/sl\/wp-json\/wp\/v2\/posts\/87197","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/prohoster.info\/sl\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/prohoster.info\/sl\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/prohoster.info\/sl\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/prohoster.info\/sl\/wp-json\/wp\/v2\/comments?post=87197"}],"version-history":[{"count":0,"href":"https:\/\/prohoster.info\/sl\/wp-json\/wp\/v2\/posts\/87197\/revisions"}],"wp:attachment":[{"href":"https:\/\/prohoster.info\/sl\/wp-json\/wp\/v2\/media?parent=87197"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/prohoster.info\/sl\/wp-json\/wp\/v2\/categories?post=87197"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/prohoster.info\/sl\/wp-json\/wp\/v2\/tags?post=87197"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}