{"id":83061,"date":"2020-05-28T01:42:22","date_gmt":"2020-05-27T23:42:22","guid":{"rendered":"https:\/\/prohoster.info\/blog\/novosti-interneta\/reliz-openssh-8-3-s-ustraneniem-uyazvimosti-v-scp"},"modified":"2020-05-28T01:42:22","modified_gmt":"2020-05-27T23:42:22","slug":"reliz-openssh-8-3-s-ustraneniem-uyazvimosti-v-scp","status":"publish","type":"post","link":"https:\/\/prohoster.info\/hr\/blog\/news\/reliz-openssh-8-3-s-ustraneniem-uyazvimosti-v-scp","title":{"rendered":"Izdanje OpenSSH 8.3 s ispravkom ranjivosti u scp","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"<p>Nakon tri mjeseca razvoja <noindex><a rel=\"nofollow\" href=\"https:\/\/lists.mindrot.org\/pipermail\/openssh-unix-dev\/2020-May\/038528.html\">predstavljen<\/a><\/noindex> izdanje <noindex><a rel=\"nofollow\" href=\"https:\/\/www.openssh.com\/\">OpenSSH 8.3<\/a><\/noindex>, otvorena implementacija klijenta i poslu\u017eitelja za rad s protokolima SSH 2.0 i SFTP. <\/p>\n<p>U novom izdanju dodana je za\u0161tita od napada na scp, \u0161to omogu\u0107uje poslu\u017eitelju da prenese druga imena datoteka koja se razlikuju od tra\u017eenih (za razliku od <noindex><a rel=\"nofollow\" href=\"https:\/\/www.opennet.ru\/opennews\/art.shtml?num=49953\">pro\u0161le ranjivosti<\/a><\/noindex>, napad ne omogu\u0107uje promjenu izabranog korisni\u010dkog direktorija ili glob-maske). Podsje\u0107amo da u SCP poslu\u017eitelj donosi odluku o tome koje datoteke i direktorije \u0107e poslati klijentu, dok klijent samo provjerava ispravnost vra\u0107enih imena objekata. Bit otkrivenog problema je u tome \u0161to se sadr\u017eaj datoteke tuma\u010di kao metapodaci datoteke ako sustavni poziv utimes zavr\u0161i pogre\u0161kom. <\/p>\n<p>Ova funkcionalnost prilikom povezivanja na server pod kontrolom zlonamjernika mo\u017ee se koristiti za spremanje drugih imena datoteka i drugog sadr\u017eaja u korisni\u010dku datote\u010dnu sustav prilikom kopiranja pomo\u0107u scp u konfiguracijama koje uzrokuju neuspjeh prilikom pozivanja utimes (na primjer, kada je utimes onemogu\u0107en politikom SELinux-a ili filtriranjem sistemskih poziva). Vjerojatnost sprovo\u0111enja stvarnih napada procjenjuje se kao minimalna, jer u tipi\u010dnim konfiguracijama poziv utimes ne zavr\u0161ava neuspjehom. Osim toga, napad ne prolazi nezapa\u017eeno \u2014 prilikom poziva scp prikazuje se gre\u0161ka pri prijenosu podataka.<\/p>\n<p>Op\u0107e promjene:<\/p>\n<ul>\n<li class=\"l\"> U sftp-u je prekinuta obrada argumenta \u201e-1\u201d po analogiji sa ssh i scp, koji je ranije bio prihva\u0107en, ali se ignorirao;\n<li class=\"l\"> U sshd-u, prilikom kori\u0161tenja IgnoreRhosts, sada se nude tri opcije: \u201eyes\u201d \u2014 ignorirati rhosts\/shosts, \u201eno\u201d \u2014 uzeti u obzir rhosts\/shosts, i \u201eshosts-only\u201d \u2014 dozvoliti \u201e.shosts\u201d, ali zabraniti \u201e.rhosts\u201d;\n<li class=\"l\"> U ssh osigurana je obrada zamjene %TOKEN u postavkama LocalForward i RemoteForward, koje se koriste za preusmjeravanje Unix soketa;\n<li class=\"l\"> Dopustilo se u\u010ditavanje otvorenih klju\u010deva iz ne\u0161ifrirane datoteke s privatnim klju\u010dem, ako ne postoji zasebna datoteka s otvorenim klju\u010dem;\n<li class=\"l\"> Ako postoji u sustavu libcrypto, ssh i sshd sada koriste implementaciju algoritma chacha20 iz te biblioteke, umjesto ugra\u0111ene prijenosne implementacije koja zaostaje po performansama;\n<li class=\"l\"> Implementirana je mogu\u0107nost ispisa sadr\u017eaja binarnog popisa opozvanih certifikata prilikom izvr\u0161avanja komande \u201essh-keygen -lQf \/path\u201d;\n<li class=\"l\"> U prijenosnoj verziji implementirano je prepoznavanje sustava u kojima signali s opcijom SA_RESTART prekinu rad select.\n<li class=\"l\"> Rije\u0161eni su problemi s izradom u sustavima HP\/UX i AIX;\n<li class=\"l\"> Uklonjeni su problemi s izradom seccomp sandboxa u nekim konfiguracijama Linuxa;\n<li class=\"l\"> Pobolj\u0161ano je prepoznavanje biblioteke libfido2 i rije\u0161eni su problemi sa sastavljanjem s opcijom \u201e--with-security-key-builtin\u201d.\n<\/ul>\n<p>Razvijatelji OpenSSH su ponovno upozorili na skoru promjenu statusa algoritama koji koriste SHA-1 he\u0161eve u kategoriju zastarjelih, u vezi s <noindex><a rel=\"nofollow\" href=\"https:\/\/www.opennet.ru\/opennews\/art.shtml?num=52149\">pove\u0107anjem<\/a><\/noindex> efikasnosti kolizijskih napada sa zadanom prefiksom (tro\u0161ak pronalaska kolizije procjenjuje se na otprilike 45 tisu\u0107a dolara). U jednom od narednih izdanja planira se onemogu\u0107iti po defaultu kori\u0161tenje algoritma digitalnog potpisa putem javnog klju\u010da \u201essh-rsa\u201d, koji se spominje u originalnom RFC-u za SSH protokol i ostaje \u0161iroko rasprostranjen u praksi (za provjeru primjene ssh-rsa u vlastitim sustavima mo\u017eete poku\u0161ati povezati se putem ssh s opcijom \u201e-oHostKeyAlgorithms=-ssh-rsa\u201d).<\/p>\n<p>Kako bi se olak\u0161ao prijelaz na nove algoritme u OpenSSH, u jednom od sljede\u0107ih izdanja prema zadanim postavkama bit \u0107e omogu\u0107ena postavka UpdateHostKeys, koja \u0107e omogu\u0107iti automatski prijelaz klijenata na pouzdanije algoritme. Me\u0111u preporu\u010denim algoritmima za migraciju spominju se rsa-sha2-256\/512 temeljen na RFC8332 RSA SHA-2 (podr\u017eava OpenSSH 7.2 i koristi se prema zadanim postavkama), ssh-ed25519 (podr\u017eava OpenSSH 6.5) i ecdsa-sha2-nistp256\/384\/521 temeljen na RFC5656 ECDSA (podr\u017eava OpenSSH 5.7). <\/p>\n<p>Po\u010dev\u0161i od pro\u0161log izdanja, \u201essh-rsa\u201d i \u201ediffie-hellman-group14-sha1\u201d su uklonjeni iz popisa CASignatureAlgorithms, koji odre\u0111uje algoritme prihvatljive za digitalno potpisivanje novih certifikata, budu\u0107i da kori\u0161tenje SHA-1 u certifikatima nosi dodatne rizike zbog toga \u0161to napada\u010d ima neograni\u010deno vrijeme za pronala\u017eenje kolizije postoje\u0107eg certifikata, dok je vrijeme napada na klju\u010deve poslu\u017eitelja ograni\u010deno na vrijeme isteka veze (LoginGraceTime). <\/p>\n<p><noindex><a rel=\"nofollow\" name=\"link\"><\/a><\/noindex><\/p>\n<p>Izvor: <a \ncontent=\"nofollow\" rel=\"nofollow\" href=\"https:\/\/www.opennet.ru\/opennews\/art.shtml?num=53039\">opennet.ru<\/a><\/p>","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":"<p>\u041f\u043e\u0441\u043b\u0435 \u0442\u0440\u0451\u0445 \u043c\u0435\u0441\u044f\u0446\u0435\u0432 \u0440\u0430\u0437\u0440\u0430\u0431\u043e\u0442\u043a\u0438 \u043f\u0440\u0435\u0434\u0441\u0442\u0430\u0432\u043b\u0435\u043d \u0440\u0435\u043b\u0438\u0437 OpenSSH 8.3, \u043e\u0442\u043a\u0440\u044b\u0442\u043e\u0439 \u0440\u0435\u0430\u043b\u0438\u0437\u0430\u0446\u0438\u0438 \u043a\u043b\u0438\u0435\u043d\u0442\u0430 \u0438 \u0441\u0435\u0440\u0432\u0435\u0440\u0430 \u0434\u043b\u044f \u0440\u0430\u0431\u043e\u0442\u044b \u043f\u043e \u043f\u0440\u043e\u0442\u043e\u043a\u043e\u043b\u0430\u043c SSH 2.0 \u0438 SFTP. \u0412 \u043d\u043e\u0432\u043e\u043c \u0432\u044b\u043f\u0443\u0441\u043a\u0435 \u0434\u043e\u0431\u0430\u0432\u043b\u0435\u043d\u0430 \u0437\u0430\u0449\u0438\u0442\u0430 \u043e\u0442 \u0430\u0442\u0430\u043a\u0438 \u043d\u0430 scp, \u043f\u043e\u0437\u0432\u043e\u043b\u044f\u044e\u0449\u0435\u0439 \u0441\u0435\u0440\u0432\u0435\u0440\u0443 \u043f\u0435\u0440\u0435\u0434\u0430\u0442\u044c \u0434\u0440\u0443\u0433\u0438\u0435 \u0438\u043c\u0435\u043d\u0430 \u0444\u0430\u0439\u043b\u043e\u0432, \u043e\u0442\u043b\u0438\u0447\u0430\u044e\u0449\u0438\u0435\u0441\u044f \u043e\u0442 \u0437\u0430\u043f\u0440\u043e\u0448\u0435\u043d\u043d\u044b\u0445 (\u0432 \u043e\u0442\u043b\u0438\u0447\u0438\u0435 \u043e\u0442 \u043f\u0440\u043e\u0448\u043b\u043e\u0439 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438, \u0430\u0442\u0430\u043a\u0430 \u043d\u0435 \u0434\u0430\u0451\u0442 \u0432\u043e\u0437\u043c\u043e\u0436\u043d\u043e\u0441\u0442\u044c \u0441\u043c\u0435\u043d\u0438\u0442\u044c \u0432\u044b\u0431\u0440\u0430\u043d\u043d\u044b\u0439 \u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u0442\u0435\u043b\u0435\u043c \u043a\u0430\u0442\u0430\u043b\u043e\u0433 \u0438\u043b\u0438 glob-\u043c\u0430\u0441\u043a\u0443). \u041d\u0430\u043f\u043e\u043c\u043d\u0438\u043c, [&hellip;]<\/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-83061","post","type-post","status-publish","format-standard","hentry","category-news"],"aioseo_notices":[],"aioseo_head":"\n\t\t<!-- All in One SEO 5.0.4 - aioseo.com -->\n\t<meta name=\"description\" content=\"\u041f\u043e\u0441\u043b\u0435 \u0442\u0440\u0451\u0445 \u043c\u0435\u0441\u044f\u0446\u0435\u0432 \u0440\u0430\u0437\u0440\u0430\u0431\u043e\u0442\u043a\u0438 \u043f\u0440\u0435\u0434\u0441\u0442\u0430\u0432\u043b\u0435\u043d \u0440\u0435\u043b\u0438\u0437\" \/>\n\t<meta name=\"robots\" content=\"max-image-preview:large\" \/>\n\t<meta name=\"author\" content=\"Yuri Gagarin\"\/>\n\t<link rel=\"canonical\" href=\"https:\/\/prohoster.info\/hr\/blog\/news\/reliz-openssh-8-3-s-ustraneniem-uyazvimosti-v-scp\" \/>\n\t\t<meta name=\"generator\" content=\"All in One SEO (AIOSEO) 5.0.4\" \/>\n\t\t<meta property=\"og:locale\" content=\"hr_HR\" \/>\n\t\t<meta property=\"og:site_name\" content=\"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\" \/>\n\t\t<meta property=\"og:type\" content=\"article\" \/>\n\t\t<meta property=\"og:title\" content=\"\ud83e\udd47\u0420\u0435\u043b\u0438\u0437 OpenSSH 8.3 \u0441 \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0438\u0435\u043c \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438 \u0432 scp | ProHoster\" \/>\n\t\t<meta property=\"og:description\" content=\"\u041f\u043e\u0441\u043b\u0435 \u0442\u0440\u0451\u0445 \u043c\u0435\u0441\u044f\u0446\u0435\u0432 \u0440\u0430\u0437\u0440\u0430\u0431\u043e\u0442\u043a\u0438 \u043f\u0440\u0435\u0434\u0441\u0442\u0430\u0432\u043b\u0435\u043d \u0440\u0435\u043b\u0438\u0437\" \/>\n\t\t<meta property=\"og:url\" content=\"https:\/\/prohoster.info\/hr\/blog\/news\/reliz-openssh-8-3-s-ustraneniem-uyazvimosti-v-scp\" \/>\n\t\t<meta property=\"og:image\" content=\"https:\/\/prohoster.info\/wp-content\/uploads\/2021\/11\/logo-350.jpg\" \/>\n\t\t<meta property=\"og:image:secure_url\" content=\"https:\/\/prohoster.info\/wp-content\/uploads\/2021\/11\/logo-350.jpg\" \/>\n\t\t<meta property=\"og:image:width\" content=\"350\" \/>\n\t\t<meta property=\"og:image:height\" content=\"350\" \/>\n\t\t<meta property=\"article:published_time\" content=\"2020-05-27T23:42:22+00:00\" \/>\n\t\t<meta property=\"article:modified_time\" content=\"2020-05-27T23:42:22+00:00\" \/>\n\t\t<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/prohoster\" \/>\n\t\t<meta property=\"article:author\" content=\"https:\/\/www.facebook.com\/prohoster\" \/>\n\t\t<!-- All in One SEO -->\n\n","aioseo_head_json":{"title":"\ud83e\udd47Izdanja OpenSSH 8.3 s ispravkom ranjivosti u scp | ProHoster","description":"Nakon tri mjeseca razvoja, predstavljen je izdanja","canonical_url":"https:\/\/prohoster.info\/hr\/blog\/news\/reliz-openssh-8-3-s-ustraneniem-uyazvimosti-v-scp","robots":"max-image-preview:large","keywords":"","webmasterTools":{"miscellaneous":""},"schema":null,"og:locale":"hr_HR","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\u0420\u0435\u043b\u0438\u0437 OpenSSH 8.3 \u0441 \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0438\u0435\u043c \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438 \u0432 scp | ProHoster","og:description":"\u041f\u043e\u0441\u043b\u0435 \u0442\u0440\u0451\u0445 \u043c\u0435\u0441\u044f\u0446\u0435\u0432 \u0440\u0430\u0437\u0440\u0430\u0431\u043e\u0442\u043a\u0438 \u043f\u0440\u0435\u0434\u0441\u0442\u0430\u0432\u043b\u0435\u043d \u0440\u0435\u043b\u0438\u0437","og:url":"https:\/\/prohoster.info\/hr\/blog\/news\/reliz-openssh-8-3-s-ustraneniem-uyazvimosti-v-scp","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":"2020-05-27T23:42:22+00:00","article:modified_time":"2020-05-27T23:42:22+00:00","article:publisher":"https:\/\/www.facebook.com\/prohoster","article:author":"https:\/\/www.facebook.com\/prohoster"},"aioseo_meta_data":{"post_id":"83061","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 15:25:24","updated":"2022-10-02 17:17:29","focus_keyword":null,"additional_keywords":null,"truseo_locale":null},"gt_translate_keys":[{"key":"link","format":"url"}],"_links":{"self":[{"href":"https:\/\/prohoster.info\/hr\/wp-json\/wp\/v2\/posts\/83061","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/prohoster.info\/hr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/prohoster.info\/hr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/prohoster.info\/hr\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/prohoster.info\/hr\/wp-json\/wp\/v2\/comments?post=83061"}],"version-history":[{"count":0,"href":"https:\/\/prohoster.info\/hr\/wp-json\/wp\/v2\/posts\/83061\/revisions"}],"wp:attachment":[{"href":"https:\/\/prohoster.info\/hr\/wp-json\/wp\/v2\/media?parent=83061"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/prohoster.info\/hr\/wp-json\/wp\/v2\/categories?post=83061"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/prohoster.info\/hr\/wp-json\/wp\/v2\/tags?post=83061"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}