{"id":170699,"date":"2026-05-15T06:24:37","date_gmt":"2026-05-15T04:24:37","guid":{"rendered":"https:\/\/prohoster.info\/blog\/novosti-interneta\/uyazvimost-v-exim-privodyashhaya-k-udalyonnomu-vypolneniyu-koda-na-servere"},"modified":"2026-05-15T06:24:37","modified_gmt":"2026-05-15T04:24:37","slug":"uyazvimost-v-exim-privodyashhaya-k-udalyonnomu-vypolneniyu-koda-na-servere","status":"publish","type":"post","link":"https:\/\/prohoster.info\/hu\/blog\/news\/uyazvimost-v-exim-privodyashhaya-k-udalyonnomu-vypolneniyu-koda-na-servere","title":{"rendered":"Exim sebezhet\u0151s\u00e9ge, amely t\u00e1voli k\u00f3dv\u00e9grehajt\u00e1shoz vezet a szerveren","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"

Az Exim levelez\u0151szerverben kritikus sebezhet\u0151s\u00e9g (CVE-2026-45185) ker\u00fclt felfedez\u00e9sre, amely lehet\u0151v\u00e9 teszi a k\u00f3d t\u00e1voli v\u00e9grehajt\u00e1s\u00e1t a szerveren. A probl\u00e9ma az Exim 4.97 verzi\u00f3t\u00f3l kezd\u0151dik, ha a GnuTLS k\u00f6nyvt\u00e1rral («USE_GNUTLS=yes») \u00e9p\u00edtett\u00e9k, \u00e9s az Exim 4.99.3 verzi\u00f3j\u00e1ban lett kijav\u00edtva. Az OpenSSL-lal \u00e9s m\u00e1s, a GnuTLS-t\u00f3l elt\u00e9r\u0151 k\u00f6nyvt\u00e1rakkal k\u00e9sz\u00fclt verzi\u00f3kat nem \u00e9rinti a sebezhet\u0151s\u00e9g. <\/p>\n

A probl\u00e9ma az m\u00e1r felszabad\u00edtott mem\u00f3ria (use-after-free) haszn\u00e1lat\u00e1b\u00f3l ad\u00f3dik a GnuTLS backendj\u00e9ben, \u00e9s kihaszn\u00e1lhat\u00f3 olyan szerverekn\u00e9l, amelyek t\u00e1mogatj\u00e1k az «ESMTP CHUNKING» kiterjeszt\u00e9st \u00e9s a BDAT parancsot, amely lehet\u0151v\u00e9 teszi a lev\u00e9l t\u00f6rzs\u00e9nek darabokban t\u00f6rt\u00e9n\u0151 \u00e1tvitel\u00e9t a DATA parancs helyett. A folyamat mem\u00f3ri\u00e1j\u00e1nak tartalm\u00e1nak megs\u00e9r\u00fcl\u00e9se akkor k\u00f6vetkezik be, amikor az \u00fcgyf\u00e9l korai TLS-sejlez\u00e9st kezdem\u00e9nyez a close_notify parancs seg\u00edts\u00e9g\u00e9vel a BDAT-on kereszt\u00fcl \u00e1tvitt \u00fczenet t\u00f6rzs\u00e9nek tov\u00e1bb\u00edt\u00e1sa sor\u00e1n, majd egy b\u00e1jtot k\u00fcld ugyanazon TCP-kapcsolaton, titkos\u00edt\u00e1s n\u00e9lk\u00fcl, ny\u00edlt sz\u00f6vegben. <\/p>\n

A close_notify parancs meg\u00e9rkez\u00e9sekor a GnuTLS h\u00e1tt\u00e9rben a TLS-munkamenet megszak\u00edt\u00e1s\u00e1\u00e9rt felel\u0151s funkci\u00f3 h\u00edv\u00f3dik meg, amely felszabad\u00edtja a munkamenettel kapcsolatos puffereket. A h\u00e1tt\u00e9rk\u00f3dban l\u00e9v\u0151 hiba miatt, a TLS-puffer felszabad\u00edt\u00e1sa ellen\u00e9re a BDAT feldolgoz\u00f3ja tov\u00e1bbra is olvassa az adatokat a folyamb\u00f3l, \u00e9s megh\u00edvja az ungetc() funkci\u00f3t, amely sor\u00e1n a titkos\u00edtatlan adatok k\u00fcld\u00e9sekor egy b\u00e1jtot \u00edr be az m\u00e1r felszabad\u00edtott pufferbe. Ez a b\u00e1jt megs\u00e9rti a kupac (heap) mem\u00f3riakezel\u0151j\u00e9nek metadat\u00e1it, ami alapot adott a k\u00f3dfuttat\u00e1s\u00e1ra alkalmas exploit kifejleszt\u00e9s\u00e9hez. szerveren<\/a>. <\/p>\n

Kezdetben a kutat\u00f3k egy r\u00e9szben m\u0171k\u00f6d\u0151 exploitot gener\u00e1ltak mesters\u00e9ges intelligencia seg\u00edts\u00e9g\u00e9vel, amely lehet\u0151v\u00e9 tette a k\u00f3d v\u00e9grehajt\u00e1s\u00e1t, de csak kontroll\u00e1lt k\u00f6rnyezetben m\u0171k\u00f6d\u00f6tt, ASLR \u00e9s PIE v\u00e9delem kiiktatott rendszereken, \u00e9s egy bizonyos libc verzi\u00f3val. Ezt k\u00f6vet\u0151en megpr\u00f3b\u00e1ltak egy emberi r\u00e9szv\u00e9tel mellett v\u00e9grehajtani egy exploit elk\u00e9sz\u00edt\u00e9s\u00e9t, ahol n\u00e9h\u00e1ny neh\u00e9zs\u00e9get siker\u00fclt lek\u00fczdeni, \u00e9s megval\u00f3s\u00edtott\u00e1k a stack c\u00edm\u00e9nek kisziv\u00e1rg\u00e1s\u00e1t, de a tervezett sebezhet\u0151s\u00e9gi bejelent\u00e9s hat\u00e1ridej\u00e9ig az exploitot nem siker\u00fclt befejezni. A kutat\u00f3k v\u00e9lem\u00e9nye szerint a mesters\u00e9ges intelligencia \u00e1ltal t\u00e1mogatott eszk\u00f6z\u00f6k m\u00e9g nem k\u00e9pesek \u00f6sszetett term\u00e9kek exploitjait l\u00e9trehozni, de rem\u00e9lik, hogy a j\u00f6v\u0151ben a t\u00f6bbi kutat\u00f3 k\u00e9pes lesz befejezni a munk\u00e1jukat \u00e9s egy teljesen m\u0171k\u00f6d\u0151 exploitot \u00edrni. <\/p>\n

A nagyobb disztrib\u00faci\u00f3k k\u00f6z\u00fcl az Exim 4.97+ verzi\u00f3ja megtal\u00e1lhat\u00f3 a Debian 13, az Ubuntu 24.04+, a SUSE\/openSUSE, az Arch Linux, az Alpine Linux 3.19+, az ALT Linux p11, a ROSA, a Gentoo, az OpenWRT, a Fedora \u00e9s az EPEL (az Exim nem r\u00e9sze a RHEL alap\u00e9rtelmezett rep\u00f3j\u00e1nak) \u00e9s a FreeBSD rendszerekben. Az Exim GnuTLS-szel k\u00e9sz\u00fclt verzi\u00f3ja alap\u00e9rtelmezett a Debian \u00e9s az Ubuntu rendszerekben, m\u00e1s disztrib\u00faci\u00f3kn\u00e1l ez meger\u0151s\u00edt\u00e9st ig\u00e9nyel. A s\u00e9r\u00fcl\u00e9kenys\u00e9g blokkol\u00e1s\u00e1ra alternat\u00edv megold\u00e1sk\u00e9nt a CHUNKING kiterjeszt\u00e9s letilthat\u00f3 a chunking_advertise_hosts be\u00e1ll\u00edt\u00e1s konfigur\u00e1ci\u00f3s f\u00e1jlban t\u00f6rt\u00e9n\u0151 m\u00f3dos\u00edt\u00e1s\u00e1val.
\n
Forr\u00e1s: opennet.ru<\/a> <\/p>","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":"

\u0412 \u043f\u043e\u0447\u0442\u043e\u0432\u043e\u043c \u0441\u0435\u0440\u0432\u0435\u0440\u0435 Exim \u0432\u044b\u044f\u0432\u043b\u0435\u043d\u0430 \u043a\u0440\u0438\u0442\u0438\u0447\u0435\u0441\u043a\u0430\u044f \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c (CVE-2026-45185), \u043f\u043e\u0437\u0432\u043e\u043b\u044f\u044e\u0449\u0430\u044f \u0443\u0434\u0430\u043b\u0451\u043d\u043d\u043e \u0434\u043e\u0431\u0438\u0442\u044c\u0441\u044f \u0432\u044b\u043f\u043e\u043b\u043d\u0435\u043d\u0438\u044f \u043a\u043e\u0434\u0430 \u043d\u0430 \u0441\u0435\u0440\u0432\u0435\u0440\u0435. \u041f\u0440\u043e\u0431\u043b\u0435\u043c\u0430 \u043f\u0440\u043e\u044f\u0432\u043b\u044f\u0435\u0442\u0441\u044f \u043d\u0430\u0447\u0438\u043d\u0430\u044f \u0441 \u0432\u0435\u0442\u043a\u0438 Exim 4.97 \u043f\u0440\u0438 \u0441\u0431\u043e\u0440\u043a\u0435 \u0441 \u0431\u0438\u0431\u043b\u0438\u043e\u0442\u0435\u043a\u043e\u0439 GnuTLS («USE_GNUTLS=yes») \u0438 \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0430 \u0432 \u0432\u044b\u043f\u0443\u0441\u043a\u0435 Exim 4.99.3. \u0421\u0431\u043e\u0440\u043a\u0438 \u0441 OpenSSL \u0438 \u0434\u0440\u0443\u0433\u0438\u043c\u0438 \u0431\u0438\u0431\u043b\u0438\u043e\u0442\u0435\u043a\u0430\u043c\u0438, \u043e\u0442\u043b\u0438\u0447\u043d\u044b\u043c\u0438 \u043e\u0442 GnuTLS, \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u043d\u0435 \u0437\u0430\u0442\u0440\u0430\u0433\u0438\u0432\u0430\u0435\u0442. \u041f\u0440\u043e\u0431\u043b\u0435\u043c\u0430 \u0432\u044b\u0437\u0432\u0430\u043d\u0430 \u043e\u0431\u0440\u0430\u0449\u0435\u043d\u0438\u0435\u043c \u043a \u0443\u0436\u0435 \u043e\u0441\u0432\u043e\u0431\u043e\u0436\u0434\u0451\u043d\u043d\u043e\u0439 \u043f\u0430\u043c\u044f\u0442\u0438 (use-after-free) \u0432 […]<\/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-170699","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 S\u00e9r\u00fcl\u00e9kenys\u00e9g az Exim rendszerben, amely t\u00e1voli k\u00f3dv\u00e9grehajt\u00e1shoz vezet a szerveren | ProHoster","description":"Az Exim levelez\u0151szerver\u00e9ben kritikus s\u00e9r\u00fcl\u00e9kenys\u00e9get (CVE-2026-45185) fedeztek fel, amely lehet\u0151v\u00e9 teszi, hogy t\u00e1volr\u00f3l k\u00f3dot futtassanak a 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\u0441\u0435\u0440\u0432\u0435\u0440\u0435.","og:url":"https:\/\/prohoster.info\/hu\/blog\/news\/uyazvimost-v-exim-privodyashhaya-k-udalyonnomu-vypolneniyu-koda-na-servere","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":"2026-05-15T04:24:37+00:00","article:modified_time":"2026-05-15T04:24:37+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\/hu\/wp-json\/wp\/v2\/posts\/170699","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/prohoster.info\/hu\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/prohoster.info\/hu\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/prohoster.info\/hu\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/prohoster.info\/hu\/wp-json\/wp\/v2\/comments?post=170699"}],"version-history":[{"count":1,"href":"https:\/\/prohoster.info\/hu\/wp-json\/wp\/v2\/posts\/170699\/revisions"}],"predecessor-version":[{"id":170706,"href":"https:\/\/prohoster.info\/hu\/wp-json\/wp\/v2\/posts\/170699\/revisions\/170706"}],"wp:attachment":[{"href":"https:\/\/prohoster.info\/hu\/wp-json\/wp\/v2\/media?parent=170699"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/prohoster.info\/hu\/wp-json\/wp\/v2\/categories?post=170699"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/prohoster.info\/hu\/wp-json\/wp\/v2\/tags?post=170699"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}