{"id":151908,"date":"2025-12-17T23:11:58","date_gmt":"2025-12-17T21:11:58","guid":{"rendered":"https:\/\/prohoster.info\/blog\/novosti-interneta\/obnovlenie-pochtovogo-servera-exim-4-99-1-s-ustraneniem-uyazvimosti"},"modified":"2025-12-17T23:11:58","modified_gmt":"2025-12-17T21:11:58","slug":"obnovlenie-pochtovogo-servera-exim-4-99-1-s-ustraneniem-uyazvimosti","status":"publish","type":"post","link":"https:\/\/prohoster.info\/cs\/blog\/news\/obnovlenie-pochtovogo-servera-exim-4-99-1-s-ustraneniem-uyazvimosti","title":{"rendered":"Aktualizace po\u0161tovn\u00edho serveru Exim 4.99.1 s odstran\u011bn\u00edm zranitelnosti","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"

Byla vyd\u00e1na opraven\u00e1 verze po\u0161tovn\u00edho serveru Exim 4.99.1, kter\u00e1 opravuje zranitelnost (CVE-2025-67896), je\u017e umo\u017e\u0148uje vzd\u00e1len\u00e9mu \u00fato\u010dn\u00edkovi po\u0161kodit obsah pam\u011bti mimo vyhrazen\u00fd buffer. Potenci\u00e1ln\u011b m\u016f\u017ee b\u00fdt probl\u00e9m vyu\u017eit pro vzd\u00e1len\u00e9 vykon\u00e1n\u00ed k\u00f3du na serveru, av\u0161ak funk\u010dn\u00ed exploit zat\u00edm nebyl p\u0159ipraven. <\/p>\n

Zranitelnost se nach\u00e1z\u00ed v k\u00f3du pro pr\u00e1ci s intern\u00ed datab\u00e1z\u00ed (Hints DB) zalo\u017een\u00e9 na SQLite, kter\u00e1 se pou\u017e\u00edv\u00e1 k ukl\u00e1d\u00e1n\u00ed do\u010dasn\u00fdch informac\u00ed, stavu doru\u010dov\u00e1n\u00ed zpr\u00e1v a informac\u00ed o intenzit\u011b odes\u00edl\u00e1n\u00ed e-mail\u016f. Probl\u00e9m je zp\u016fsoben t\u00edm, \u017ee z\u00e1znamy z datab\u00e1ze byly p\u0159\u00edmo p\u0159evedeny do intern\u00ed struktury «dbdata_ratelimit_unique» bez n\u00e1le\u017eit\u00e9ho ov\u011b\u0159en\u00ed. Vznikla situace, kdy byl vytvo\u0159en fixn\u00ed pole «bloom» o velikosti 40 bajt\u016f, zat\u00edmco obsah pole «bloom_size», ur\u010duj\u00edc\u00ed po\u010det zapisovan\u00fdch prvk\u016f do pole, z\u00e1visel na velikosti dat v datab\u00e1zi. \u00dato\u010dn\u00edk mohl zajistit z\u00e1pis za hranice p\u0159id\u011blen\u00e9ho bufferu t\u00edm, \u017ee vlo\u017eil do datab\u00e1ze data (vyu\u017eit\u00edm dal\u0161\u00ed zranitelnosti), p\u0159i kter\u00fdch pole «bloom_size» nabylo hodnoty mnohem v\u011bt\u0161\u00ed, ne\u017e je velikost pole. <\/p>\n

Probl\u00e9m se projevuje ve verz\u00edch Exim 4.99 a 4.98.2 a t\u00fdk\u00e1 se pouze konfigurac\u00ed s ACL ratelimit, ve kter\u00fdch se pou\u017e\u00edvaj\u00ed parametry «unique» nebo «per_addr» (nap\u0159\u00edklad «warn ratelimit = 100 \/ 1h \/ per_addr \/ $sender_address» nebo «warn ratelimit = 100 \/ 1h \/ per_rcpt \/ unique=$sender_address»). K proveden\u00ed \u00fatoku mus\u00ed b\u00fdt Exim sestaven s podporou SQLite (USE_SQLITE=yes), aktivovanou v konfigura\u010dn\u00edm souboru (hints_database = sqlite). Ve zraniteln\u00fdch konfigurac\u00edch se p\u0159i spu\u0161t\u011bn\u00ed «exim -bV» zobrazuje «Hints DB: Using sqlite3». <\/p>\n

Z velk\u00fdch distribuc\u00ed byly probl\u00e9mov\u00e9 verze pou\u017e\u00edv\u00e1ny v Debian 13, Ubuntu 25.10, SUSE\/openSUSE, Arch Linux, Fedora a FreeBSD. RHEL a odvozen\u00e9 distribuce probl\u00e9mu nejsou vystaveny, proto\u017ee Exim nen\u00ed sou\u010d\u00e1st\u00ed jejich standardn\u00edho repozit\u00e1\u0159e bal\u00ed\u010dk\u016f (v EPEL aktualizace bal\u00ed\u010dku exim zat\u00edm nebyla vyd\u00e1na). <\/p>\n

Tak\u00e9 byl zaznamen\u00e1n nov\u00fd vektor pro exploitaci zranitelnosti CVE-2025-26794, kter\u00e1 byla odstran\u011bna ve febru\u00e1rov\u00e9m vyd\u00e1n\u00ed Exim 4.98.1. Zranitelnost umo\u017e\u0148uje prov\u00e1d\u011bt injekci SQL k\u00f3du do intern\u00ed datab\u00e1ze (Hints DB). D\u0159\u00edve uveden\u00e9 opravy neescape-ovaly jednoduch\u00e9 uvozovky. P\u0159\u00edklad p\u0159\u00edkazu MAIL FROM, kter\u00fd vede k injekci SQL k\u00f3du: «MAIL FROM:<«x’\/**\/UNION\/**\/SELECT\/**\/X'<hex_blob>’—«@attacker.com>». Tato zranitelnost m\u016f\u017ee b\u00fdt vyu\u017eita jako v\u00fdchoz\u00ed bod pro vytvo\u0159en\u00ed podm\u00ednek pro vznik v\u00fd\u0161e popsan\u00e9ho p\u0159ete\u010den\u00ed bufferu.
\n
Zdroj: opennet.ru<\/a> <\/p>","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":"

\u041e\u043f\u0443\u0431\u043b\u0438\u043a\u043e\u0432\u0430\u043d \u043a\u043e\u0440\u0440\u0435\u043a\u0442\u0438\u0440\u0443\u044e\u0449\u0438\u0439 \u0432\u044b\u043f\u0443\u0441\u043a \u043f\u043e\u0447\u0442\u043e\u0432\u043e\u0433\u043e \u0441\u0435\u0440\u0432\u0435\u0440\u0430 Exim 4.99.1, \u0432 \u043a\u043e\u0442\u043e\u0440\u043e\u043c \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0430 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c (CVE-2025-67896), \u043f\u043e\u0437\u0432\u043e\u043b\u044f\u044e\u0449\u0430\u044f \u0443\u0434\u0430\u043b\u0451\u043d\u043d\u043e\u043c\u0443 \u0430\u0442\u0430\u043a\u0443\u044e\u0449\u0435\u043c\u0443 \u043f\u043e\u0432\u0440\u0435\u0434\u0438\u0442\u044c \u0441\u043e\u0434\u0435\u0440\u0436\u0438\u043c\u043e\u0435 \u043f\u0430\u043c\u044f\u0442\u0438 \u0432\u043d\u0435 \u0432\u044b\u0434\u0435\u043b\u0435\u043d\u043d\u043e\u0433\u043e \u0431\u0443\u0444\u0435\u0440\u0430. 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\u0431\u0430\u0437\u0435 SQLite, \u0438\u0441\u043f\u043e\u043b\u044c\u0437\u0443\u0435\u043c\u043e\u0439 \u0434\u043b\u044f \u0445\u0440\u0430\u043d\u0435\u043d\u0438\u044f \u0432\u0440\u0435\u043c\u0435\u043d\u043d\u043e\u0439 […]<\/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-151908","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\udd47Aktualizace po\u0161tovn\u00edho serveru Exim 4.99.1 s odstran\u011bn\u00edm zranitelnosti | ProHoster","description":"Byla zve\u0159ejn\u011bna opravn\u00e1 verze po\u0161tovn\u00edho serveru Exim 4.99.1, ve kter\u00e9 byla odstran\u011bna zranitelnost (CVE-2025-67896), umo\u017e\u0148uj\u00edc\u00ed vzd\u00e1len\u00e9mu \u00fato\u010dn\u00edkovi po\u0161kodit obsah pam\u011bti mimo vyhrazen\u00fd buffer.","canonical_url":"https:\/\/prohoster.info\/cs\/blog\/news\/obnovlenie-pochtovogo-servera-exim-4-99-1-s-ustraneniem-uyazvimosti","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 \u043f\u043e\u0447\u0442\u043e\u0432\u043e\u0433\u043e \u0441\u0435\u0440\u0432\u0435\u0440\u0430 Exim 4.99.1 \u0441 \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0438\u0435\u043c \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438 | ProHoster","og:description":"\u041e\u043f\u0443\u0431\u043b\u0438\u043a\u043e\u0432\u0430\u043d \u043a\u043e\u0440\u0440\u0435\u043a\u0442\u0438\u0440\u0443\u044e\u0449\u0438\u0439 \u0432\u044b\u043f\u0443\u0441\u043a \u043f\u043e\u0447\u0442\u043e\u0432\u043e\u0433\u043e \u0441\u0435\u0440\u0432\u0435\u0440\u0430 Exim 4.99.1, \u0432 \u043a\u043e\u0442\u043e\u0440\u043e\u043c \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0430 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c (CVE-2025-67896), \u043f\u043e\u0437\u0432\u043e\u043b\u044f\u044e\u0449\u0430\u044f \u0443\u0434\u0430\u043b\u0451\u043d\u043d\u043e\u043c\u0443 \u0430\u0442\u0430\u043a\u0443\u044e\u0449\u0435\u043c\u0443 \u043f\u043e\u0432\u0440\u0435\u0434\u0438\u0442\u044c \u0441\u043e\u0434\u0435\u0440\u0436\u0438\u043c\u043e\u0435 \u043f\u0430\u043c\u044f\u0442\u0438 \u0432\u043d\u0435 \u0432\u044b\u0434\u0435\u043b\u0435\u043d\u043d\u043e\u0433\u043e \u0431\u0443\u0444\u0435\u0440\u0430.","og:url":"https:\/\/prohoster.info\/cs\/blog\/news\/obnovlenie-pochtovogo-servera-exim-4-99-1-s-ustraneniem-uyazvimosti","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":"2025-12-17T21:11:58+00:00","article:modified_time":"2025-12-17T21:11:58+00:00","article:publisher":"https:\/\/www.facebook.com\/prohoster","article:author":"https:\/\/www.facebook.com\/prohoster"},"aioseo_meta_data":{"post_id":"151908","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":"default","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":"2026-01-20 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