{"id":107307,"date":"2023-03-16T12:48:10","date_gmt":"2023-03-16T10:48:10","guid":{"rendered":"https:\/\/prohoster.info\/?p=107307"},"modified":"2023-03-17T13:35:25","modified_gmt":"2023-03-17T11:35:25","slug":"obnovlenie-openssh-9-3-s-ustraneniem-problem-s-bezopasnostyu","status":"publish","type":"post","link":"https:\/\/prohoster.info\/cs\/blog\/news\/obnovlenie-openssh-9-3-s-ustraneniem-problem-s-bezopasnostyu","title":{"rendered":"Aktualizace OpenSSH 9.3 s opravou bezpe\u010dnostn\u00edch probl\u00e9m\u016f","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"<p>Byl vyd\u00e1n OpenSSH 9.3, otev\u0159en\u00e1 implementace klienta a serveru pro pr\u00e1ci se servery SSH 2.0 a SFTP. Nov\u00e9 verze opravuj\u00ed bezpe\u010dnostn\u00ed probl\u00e9my:    <\/p>\n<ul>\n<li class=\"l\"> V n\u00e1stroji ssh-add byla zji\u0161t\u011bna logick\u00e1 chyba, kter\u00e1 p\u0159i p\u0159id\u00e1v\u00e1n\u00ed kl\u00ed\u010d\u016f pro chytr\u00e9 karty do ssh-agentu nezohled\u0148ovala omezen\u00ed definovan\u00e1 pomoc\u00ed volby \u201essh-add -h\u201c. V\u00fdsledkem bylo, \u017ee do agenta byl p\u0159id\u00e1n kl\u00ed\u010d, na kter\u00fd se tato omezen\u00ed, umo\u017e\u0148uj\u00edc\u00ed p\u0159ipojen\u00ed pouze z ur\u010dit\u00fdch hostitel\u016f, nevztahovala.\n<li class=\"l\"> V n\u00e1stroji ssh byla zji\u0161t\u011bna zranitelnost, kter\u00e1 m\u016f\u017ee v\u00e9st k \u010dten\u00ed dat z oblasti z\u00e1sobn\u00edku mimo p\u0159id\u011blen\u00fd buffer p\u0159i zpracov\u00e1n\u00ed speci\u00e1ln\u011b form\u00e1tovan\u00fdch DNS odpov\u011bd\u00ed, pokud je v konfigura\u010dn\u00edm souboru nastavena volba VerifyHostKeyDNS. Probl\u00e9m existuje ve vestav\u011bn\u00e9 implementaci funkce getrrsetbyname(), kter\u00e1 se pou\u017e\u00edv\u00e1 v p\u0159enositeln\u00fdch verz\u00edch OpenSSH, kompilovan\u00fdch bez pou\u017eit\u00ed extern\u00ed knihovny ldns (\u2014with-ldns) a na syst\u00e9mech se standardn\u00edmi knihovnami, kter\u00e9 nepodporuj\u00ed vol\u00e1n\u00ed getrrsetbyname(). Mo\u017enost exploatace zranitelnosti, krom\u011b iniciov\u00e1n\u00ed odm\u00edtnut\u00ed slu\u017eby klienta ssh, je hodnocena jako m\u00e1lo pravd\u011bpodobn\u00e1.  <\/ul>\n<p>D\u00e1le lze zm\u00ednit zranitelnost v knihovn\u011b libskey, kter\u00e1 je sou\u010d\u00e1st\u00ed OpenBSD a kterou pou\u017e\u00edv\u00e1 OpenSSH. Probl\u00e9m p\u0159etrv\u00e1v\u00e1 od roku 1997 a m\u016f\u017ee v\u00e9st k p\u0159ete\u010den\u00ed bufferu na z\u00e1sobn\u00edku p\u0159i zpracov\u00e1n\u00ed speci\u00e1ln\u011b form\u00e1tovan\u00fdch jmen hostitel\u016f. Je uvedeno, \u017ee i kdy\u017e m\u016f\u017ee b\u00fdt projev zranitelnosti iniciov\u00e1n vzd\u00e1len\u011b p\u0159es OpenSSH, v praxi je zranitelnost bezcenn\u00e1, proto\u017ee pro jej\u00ed projev mus\u00ed jm\u00e9no napaden\u00e9ho hostitele (\/etc\/hostname) obsahovat v\u00edce ne\u017e 126 znak\u016f, a buffer m\u016f\u017ee b\u00fdt p\u0159ete\u010den pouze znaky s nulov\u00fdm k\u00f3dem (\u2019\u2019).        <\/p>\n<p>Mezi zm\u011bnami nesouvisej\u00edc\u00edmi s bezpe\u010dnost\u00ed:  <\/p>\n<ul>\n<li class=\"l\"> Do ssh-keygen a ssh-keyscan byla p\u0159id\u00e1na podpora parametru \u201e-Ohashalg=sha1|sha256\u201c pro v\u00fdb\u011br algoritmu zobrazen\u00ed otisk\u016f SSHFP.\n<li class=\"l\"> Do sshd byla p\u0159id\u00e1na volba \u201e-G\u201c pro anal\u00fdzu a zobrazen\u00ed aktivn\u00ed konfigurace bez pokusu o na\u010dten\u00ed soukrom\u00fdch kl\u00ed\u010d\u016f a bez prov\u00e1d\u011bn\u00ed dal\u0161\u00edch kontrol, co\u017e umo\u017e\u0148uje ov\u011b\u0159ovat konfiguraci p\u0159ed generov\u00e1n\u00edm kl\u00ed\u010d\u016f a prov\u00e1d\u011bt kontrolu neprivilegovan\u00fdmi u\u017eivateli.\n<li class=\"l\"> V sshd byla pos\u00edlena izolace na platform\u011b Linux, kter\u00e1 vyu\u017e\u00edv\u00e1 mechanismy filtrov\u00e1n\u00ed syst\u00e9mov\u00fdch vol\u00e1n\u00ed seccomp a seccomp-bpf. Do seznamu povolen\u00fdch syst\u00e9mov\u00fdch vol\u00e1n\u00ed byly p\u0159id\u00e1ny p\u0159\u00edznaky k mmap, madvise a futex.    <\/ul>\n<p>Zdroj: <a content=\"nofollow\" rel=\"nofollow\" href=\"https:\/\/www.opennet.ru\/opennews\/art.shtml?num=58801\">opennet.ru<\/a> <\/p>","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":"<p>\u041e\u043f\u0443\u0431\u043b\u0438\u043a\u043e\u0432\u0430\u043d \u0440\u0435\u043b\u0438\u0437 OpenSSH 9.3, \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\u0439 \u0432\u0435\u0440\u0441\u0438\u0438 \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u044b \u043f\u0440\u043e\u0431\u043b\u0435\u043c\u044b \u0441 \u0431\u0435\u0437\u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u044c\u044e: \u0412 \u0443\u0442\u0438\u043b\u0438\u0442\u0435 ssh-add \u0432\u044b\u044f\u0432\u043b\u0435\u043d\u0430 \u043b\u043e\u0433\u0438\u0447\u0435\u0441\u043a\u0430\u044f \u043e\u0448\u0438\u0431\u043a\u0430, \u0438\u0437-\u0437\u0430 \u043a\u043e\u0442\u043e\u0440\u043e\u0439 \u043f\u0440\u0438 \u0434\u043e\u0431\u0430\u0432\u043b\u0435\u043d\u0438\u0438 \u0432 ssh-agent \u043a\u043b\u044e\u0447\u0435\u0439 \u0434\u043b\u044f \u0441\u043c\u0430\u0440\u0442\u043a\u0430\u0440\u0442 \u0430\u0433\u0435\u043d\u0442\u0443 \u043d\u0435 \u043f\u0435\u0440\u0435\u0434\u0430\u0432\u0430\u043b\u0438\u0441\u044c \u043e\u0433\u0440\u0430\u043d\u0438\u0447\u0435\u043d\u0438\u044f, \u0437\u0430\u0434\u0430\u0432\u0430\u0435\u043c\u044b\u0435 \u043f\u0440\u0438 \u043f\u043e\u043c\u043e\u0449\u0438 \u043e\u043f\u0446\u0438\u0438 &#171;ssh-add -h&#187;. \u0412 \u0438\u0442\u043e\u0433\u0435 \u0432 \u0430\u0433\u0435\u043d\u0442 \u0434\u043e\u0431\u0430\u0432\u043b\u044f\u043b\u0441\u044f \u043a\u043b\u044e\u0447, [&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-107307","post","type-post","status-publish","format-standard","hentry","category-news"],"aioseo_notices":[],"aioseo_head":"\n\t\t<!-- All in One SEO 5.0.3 - aioseo.com -->\n\t<meta name=\"description\" content=\"\u041e\u043f\u0443\u0431\u043b\u0438\u043a\u043e\u0432\u0430\u043d \u0440\u0435\u043b\u0438\u0437 OpenSSH 9.3, \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 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pro pr\u00e1ci s protokoly SSH 2.0 a SFTP.","canonical_url":"https:\/\/prohoster.info\/cs\/blog\/news\/obnovlenie-openssh-9-3-s-ustraneniem-problem-s-bezopasnostyu","robots":"max-image-preview:large","keywords":"","webmasterTools":{"miscellaneous":""},"schema":null,"og:locale":"cs_CZ","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\u041e\u0431\u043d\u043e\u0432\u043b\u0435\u043d\u0438\u0435 OpenSSH 9.3 \u0441 \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0438\u0435\u043c \u043f\u0440\u043e\u0431\u043b\u0435\u043c \u0441 \u0431\u0435\u0437\u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u044c\u044e | 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SFTP.","og:url":"https:\/\/prohoster.info\/cs\/blog\/news\/obnovlenie-openssh-9-3-s-ustraneniem-problem-s-bezopasnostyu","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":"2023-03-16T10:48:10+00:00","article:modified_time":"2023-03-17T11:35:25+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\/cs\/wp-json\/wp\/v2\/posts\/107307","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/prohoster.info\/cs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/prohoster.info\/cs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/prohoster.info\/cs\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/prohoster.info\/cs\/wp-json\/wp\/v2\/comments?post=107307"}],"version-history":[{"count":0,"href":"https:\/\/prohoster.info\/cs\/wp-json\/wp\/v2\/posts\/107307\/revisions"}],"wp:attachment":[{"href":"https:\/\/prohoster.info\/cs\/wp-json\/wp\/v2\/media?parent=107307"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/prohoster.info\/cs\/wp-json\/wp\/v2\/categories?post=107307"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/prohoster.info\/cs\/wp-json\/wp\/v2\/tags?post=107307"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}