{"id":172666,"date":"2026-05-19T00:24:49","date_gmt":"2026-05-18T22:24:49","guid":{"rendered":"https:\/\/prohoster.info\/blog\/novosti-interneta\/v-exim-4-99-3-ustranena-uyazvimost-pozvolyayushhaya-udalyonnoe-vypolnenie-koda-pri-ispolzovanii-gnutls"},"modified":"2026-05-19T00:24:49","modified_gmt":"2026-05-18T22:24:49","slug":"v-exim-4-99-3-ustranena-uyazvimost-pozvolyayushhaya-udalyonnoe-vypolnenie-koda-pri-ispolzovanii-gnutls","status":"publish","type":"post","link":"https:\/\/prohoster.info\/sk\/blog\/news\/v-exim-4-99-3-ustranena-uyazvimost-pozvolyayushhaya-udalyonnoe-vypolnenie-koda-pri-ispolzovanii-gnutls","title":{"rendered":"V Exim 4.99.3 bola odstr\u00e1nen\u00e1 zranite\u013enos\u0165, umo\u017e\u0148uj\u00faca vzdialen\u00e9 vykon\u00e1vanie k\u00f3du pri pou\u017eit\u00ed GnuTLS","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"

V\u00fdvoj\u00e1ri po\u0161tov\u00e9ho servera Exim vydali opravn\u00fa verziu Exim 4.99.3<\/strong>, ktor\u00e1 odstra\u0148uje zranite\u013enos\u0165 v niektor\u00fdch konfigur\u00e1ci\u00e1ch po\u0161tov\u00e9ho agenta. Probl\u00e9m m\u00e1 vn\u00fatorn\u00fd identifik\u00e1tor EXIM-Security-2026-05-01.1<\/strong>; v ofici\u00e1lnom ozn\u00e1men\u00ed sa objavuje aj ako CVE-TBD<\/strong>.<\/p>\n

Zranite\u013enos\u0165 patr\u00ed do triedy Remote Use-After-Free<\/strong> a prejavuje sa pri rozboru tela spr\u00e1vy BDAT<\/strong> pri pr\u00e1ci TLS cez GnuTLS<\/strong>. BDAT sa pou\u017e\u00edva v SMTP roz\u0161\u00edren\u00ed CHUNKING<\/strong> na prenos tela spr\u00e1vy po blokoch. Pod\u013ea popisu Exim m\u00f4\u017ee by\u0165 chyba sp\u00f4soben\u00e1, ke\u010f klient po\u010das prenosu BDAT odo\u0161le TLS ozn\u00e1menie close_notify pred dokon\u010den\u00edm prenosu tela a n\u00e1sledne prid\u00e1 \u010fal\u0161\u00ed bajt v r\u00e1mci toho ist\u00e9ho TCP spojenia.<\/p>\n

V takejto sekvencii m\u00f4\u017ee Exim zap\u00edsa\u0165 d\u00e1ta do vyrovn\u00e1vacej pam\u00e4te, ktor\u00e1 u\u017e bola uvo\u013enen\u00e1 pri ukon\u010den\u00ed TLS rel\u00e1cie. To vedie k po\u0161kodeniu haldy a potenci\u00e1lne m\u00f4\u017ee by\u0165 pou\u017eit\u00e9 na vykonanie k\u00f3du. V ozn\u00e1men\u00ed sa zd\u00f4raz\u0148uje, \u017ee \u00fato\u010dn\u00edkovi sta\u010d\u00ed ma\u0165 mo\u017enos\u0165 vytvori\u0165 TLS spojenie a pou\u017e\u00edva\u0165 SMTP roz\u0161\u00edrenie CHUNKING \/ BDAT<\/strong>.<\/p>\n

Probl\u00e9m sa t\u00fdka Exim 4.97, 4.98, 4.99, 4.99.1 a 4.99.2<\/strong>, ale len zostavenia, ktor\u00e9 boli zostaven\u00e9 s podporou GnuTLS<\/strong>. V ofici\u00e1lnej dokument\u00e1cii je to formulovan\u00e9 ako konfigur\u00e1cie s USE_GNUTLS=yes; zostavenia vyu\u017e\u00edvaj\u00face OpenSSL<\/strong> alebo in\u00e9 TLS kni\u017enice touto zranite\u013enos\u0165ou nie s\u00fa postihnut\u00e9. V ozn\u00e1men\u00ed Exim sa tie\u017e osobitne uv\u00e1dza, \u017ee zranite\u013en\u00e9 s\u00fa konfigur\u00e1cie, kde s\u00fa vyhl\u00e1sen\u00e9 STARTTLS<\/strong> a CHUNKING<\/strong>.<\/p>\n

Oprava je zahrnut\u00e1 v Exim 4.99.3<\/strong>. Pod\u013ea popisu v\u00fdvoj\u00e1rov patch zaru\u010duje \u010dist\u00e9 obnovenie z\u00e1sobn\u00edka spracovania vstupu pri prij\u00edman\u00ed TLS close_notify po\u010das akt\u00edvneho prenosu BDAT, \u010do zabra\u0148uje \u010fal\u0161iemu vyu\u017e\u00edvaniu zastaran\u00fdch ukazovate\u013eov. In\u00fd zn\u00e1my sp\u00f4sob, ako t\u00fato problematiku \u00faplne uzavrie\u0165, okrem aktualiz\u00e1cie, v odpor\u00fa\u010daniach nie je uveden\u00fd.<\/p>\n

V\u00fdvoj\u00e1ri Exim dostali hl\u00e1senie o chybe 1. m\u00e1ja 2026<\/strong> od Federica Kirschbauma z XBOW Security<\/strong>. Po overen\u00ed spr\u00e1vy sa oprava pripravovala v uzavret\u00fdch repozit\u00e1roch, 7. m\u00e1ja bola probl\u00e9m ozn\u00e1men\u00fd distrib\u00fatorom cez uzavret\u00fd mailing list, 10. m\u00e1ja im poskytli obmedzen\u00fd pr\u00edstup k oprav\u00e1m a 12. m\u00e1ja 2026<\/strong> bola zverejnen\u00e1 odpor\u00fa\u010dania a samotn\u00e1 verzia s opravou.<\/p>\n

Spr\u00e1vcovia po\u0161tov\u00fdch serverov by mali skontrolova\u0165 pou\u017e\u00edvan\u00fa verziu Exim a TLS backend zostavy. Ak server<\/a> funguje na Exim od 4.97 do 4.99.2 vr\u00e1tane, zostaven\u00fd s GnuTLS a hl\u00e1si STARTTLS spolu s CHUNKING, projekt Exim odpor\u00fa\u010da \u010d\u00edm sk\u00f4r prejs\u0165 na Exim 4.99.3<\/strong> alebo nov\u0161iu verziu. Opraven\u00e9 zdrojov\u00e9 k\u00f3dy s\u00fa dostupn\u00e9 v vetve exim-4.99+fixes a v ozna\u010den\u00ed exim-4.99.3, ako aj vo forme tarball arch\u00edvov na be\u017en\u00fdch miestach na stiahnutie Exim.<\/p>\n

Zdroj: linux.org.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 \u043f\u043e\u0447\u0442\u043e\u0432\u043e\u0433\u043e \u0441\u0435\u0440\u0432\u0435\u0440\u0430 Exim \u0432\u044b\u043f\u0443\u0441\u0442\u0438\u043b\u0438 \u043a\u043e\u0440\u0440\u0435\u043a\u0442\u0438\u0440\u0443\u044e\u0449\u0438\u0439 \u0440\u0435\u043b\u0438\u0437 Exim 4.99.3, \u0443\u0441\u0442\u0440\u0430\u043d\u044f\u044e\u0449\u0438\u0439 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u0432 \u043d\u0435\u043a\u043e\u0442\u043e\u0440\u044b\u0445 \u043a\u043e\u043d\u0444\u0438\u0433\u0443\u0440\u0430\u0446\u0438\u044f\u0445 \u043f\u043e\u0447\u0442\u043e\u0432\u043e\u0433\u043e \u0430\u0433\u0435\u043d\u0442\u0430. \u041f\u0440\u043e\u0431\u043b\u0435\u043c\u0430 \u043f\u0440\u043e\u0445\u043e\u0434\u0438\u0442 \u043f\u043e\u0434 \u0432\u043d\u0443\u0442\u0440\u0435\u043d\u043d\u0438\u043c \u0438\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440\u043e\u043c EXIM-Security-2026-05-01.1; \u0432 \u043e\u0444\u0438\u0446\u0438\u0430\u043b\u044c\u043d\u043e\u043c \u0443\u0432\u0435\u0434\u043e\u043c\u043b\u0435\u043d\u0438\u0438 \u0442\u0430\u043a\u0436\u0435 \u0444\u0438\u0433\u0443\u0440\u0438\u0440\u0443\u0435\u0442 \u043a\u0430\u043a CVE-TBD. \u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u043e\u0442\u043d\u043e\u0441\u0438\u0442\u0441\u044f \u043a \u043a\u043b\u0430\u0441\u0441\u0443 Remote Use-After-Free \u0438 \u043f\u0440\u043e\u044f\u0432\u043b\u044f\u0435\u0442\u0441\u044f \u043f\u0440\u0438 \u0440\u0430\u0437\u0431\u043e\u0440\u0435 \u0442\u0435\u043b\u0430 \u0441\u043e\u043e\u0431\u0449\u0435\u043d\u0438\u044f BDAT \u043f\u0440\u0438 \u0440\u0430\u0431\u043e\u0442\u0435 TLS \u0447\u0435\u0440\u0435\u0437 GnuTLS. BDAT \u0438\u0441\u043f\u043e\u043b\u044c\u0437\u0443\u0435\u0442\u0441\u044f \u0432 SMTP-\u0440\u0430\u0441\u0448\u0438\u0440\u0435\u043d\u0438\u0438 CHUNKING \u0434\u043b\u044f \u043f\u0435\u0440\u0435\u0434\u0430\u0447\u0438 \u0442\u0435\u043b\u0430 […]<\/p>\n","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"author":8,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[702],"tags":[],"class_list":["post-172666","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\udd47V Exim 4.99.3 bola odstr\u00e1nen\u00e1 zranite\u013enos\u0165, ktor\u00e1 umo\u017e\u0148ovala vzdialen\u00e9 vykon\u00e1vanie k\u00f3du pri pou\u017eit\u00ed GnuTLS | ProHoster","description":"Developeri po\u0161tov\u00e9ho servera Exim vydali korek\u010dn\u00fd release Exim 4.99.3, ktor\u00fd odstra\u0148uje zranite\u013enos\u0165 v niektor\u00fdch konfigur\u00e1ci\u00e1ch po\u0161tov\u00e9ho agenta.","canonical_url":"https:\/\/prohoster.info\/sk\/blog\/news\/v-exim-4-99-3-ustranena-uyazvimost-pozvolyayushhaya-udalyonnoe-vypolnenie-koda-pri-ispolzovanii-gnutls","robots":"max-image-preview:large","keywords":"","webmasterTools":{"miscellaneous":""},"schema":null,"og:locale":"sk_SK","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\u0412 Exim 4.99.3 \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0430 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c, \u043f\u043e\u0437\u0432\u043e\u043b\u044f\u044e\u0449\u0430\u044f \u0443\u0434\u0430\u043b\u0451\u043d\u043d\u043e\u0435 \u0432\u044b\u043f\u043e\u043b\u043d\u0435\u043d\u0438\u0435 \u043a\u043e\u0434\u0430 \u043f\u0440\u0438 \u0438\u0441\u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u043d\u0438\u0438 GnuTLS | ProHoster","og:description":"\u0420\u0430\u0437\u0440\u0430\u0431\u043e\u0442\u0447\u0438\u043a\u0438 \u043f\u043e\u0447\u0442\u043e\u0432\u043e\u0433\u043e \u0441\u0435\u0440\u0432\u0435\u0440\u0430 Exim \u0432\u044b\u043f\u0443\u0441\u0442\u0438\u043b\u0438 \u043a\u043e\u0440\u0440\u0435\u043a\u0442\u0438\u0440\u0443\u044e\u0449\u0438\u0439 \u0440\u0435\u043b\u0438\u0437 Exim 4.99.3, \u0443\u0441\u0442\u0440\u0430\u043d\u044f\u044e\u0449\u0438\u0439 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u0432 \u043d\u0435\u043a\u043e\u0442\u043e\u0440\u044b\u0445 \u043a\u043e\u043d\u0444\u0438\u0433\u0443\u0440\u0430\u0446\u0438\u044f\u0445 \u043f\u043e\u0447\u0442\u043e\u0432\u043e\u0433\u043e \u0430\u0433\u0435\u043d\u0442\u0430.","og:url":"https:\/\/prohoster.info\/sk\/blog\/news\/v-exim-4-99-3-ustranena-uyazvimost-pozvolyayushhaya-udalyonnoe-vypolnenie-koda-pri-ispolzovanii-gnutls","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":"2026-05-18T22:24:49+00:00","article:modified_time":"2026-05-18T22:24:49+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\/sk\/wp-json\/wp\/v2\/posts\/172666","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/prohoster.info\/sk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/prohoster.info\/sk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/prohoster.info\/sk\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/prohoster.info\/sk\/wp-json\/wp\/v2\/comments?post=172666"}],"version-history":[{"count":1,"href":"https:\/\/prohoster.info\/sk\/wp-json\/wp\/v2\/posts\/172666\/revisions"}],"predecessor-version":[{"id":173168,"href":"https:\/\/prohoster.info\/sk\/wp-json\/wp\/v2\/posts\/172666\/revisions\/173168"}],"wp:attachment":[{"href":"https:\/\/prohoster.info\/sk\/wp-json\/wp\/v2\/media?parent=172666"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/prohoster.info\/sk\/wp-json\/wp\/v2\/categories?post=172666"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/prohoster.info\/sk\/wp-json\/wp\/v2\/tags?post=172666"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}