{"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\/sv\/blog\/news\/v-exim-4-99-3-ustranena-uyazvimost-pozvolyayushhaya-udalyonnoe-vypolnenie-koda-pri-ispolzovanii-gnutls","title":{"rendered":"I Exim 4.99.3 har en s\u00e5rbarhet \u00e5tg\u00e4rdats som m\u00f6jligg\u00f6r fj\u00e4rrk\u00f6rning av kod vid anv\u00e4ndning av GnuTLS","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"<p>Utvecklarna av e-postservern Exim har sl\u00e4ppt en korrigeringsrelease <strong>Exim 4.99.3<\/strong>, som \u00e5tg\u00e4rdar en s\u00e5rbarhet i vissa konfigurationer av e-postagenten. Problemet har ett internt ID <strong>EXIM-Security-2026-05-01.1<\/strong>; i det officiella meddelandet n\u00e4mns det ocks\u00e5 som <strong>CVE-TBD<\/strong>.<\/p>\n<p>S\u00e5rbarheten tillh\u00f6r klassen <strong>Remote Use-After-Free<\/strong> och uppst\u00e5r vid analys av meddelandekroppen <strong>BDAT<\/strong> vid arbete med TLS genom <strong>GnuTLS<\/strong>. BDAT anv\u00e4nds i SMTP-till\u00e4gget <strong>CHUNKING<\/strong> f\u00f6r att \u00f6verf\u00f6ra meddelandekroppen i block. Enligt Exims beskrivning kan felet utl\u00f6sas n\u00e4r klienten under \u00f6verf\u00f6ringen av BDAT skickar TLS-meddelandet close_notify innan \u00f6verf\u00f6ringen av kroppen avslutas, och sedan l\u00e4gger till en extra byte inom samma TCP-anslutning.<\/p>\n<p>I denna sekvens kan Exim skriva data till ett minnesbuffer som redan har frigjorts vid avslutningen av TLS-sessionen. Detta leder till heapkorruption och kan potentiellt utnyttjas f\u00f6r kodexekvering. I meddelandet betonas att angriparen endast beh\u00f6ver ha m\u00f6jlighet att etablera en TLS-anslutning och anv\u00e4nda SMTP-till\u00e4gget <strong>CHUNKING \/ BDAT<\/strong>.<\/p>\n<p>Problemet p\u00e5verkar <strong>Exim 4.97, 4.98, 4.99, 4.99.1 och 4.99.2<\/strong>, men endast versioner som har byggts med st\u00f6d f\u00f6r <strong>GnuTLS<\/strong>. I den officiella dokumentationen anges detta som konfigurationer med USE_GNUTLS=yes; versioner som anv\u00e4nder <strong>OpenSSL<\/strong> eller andra TLS-bibliotek ber\u00f6rs inte av denna s\u00e5rbarhet. Ocks\u00e5 i Exims meddelande anges det tydligt att konfigurationer d\u00e4r <strong>STARTTLS<\/strong> och <strong>CHUNKING<\/strong>.<\/p>\n<p>\u00e5tg\u00e4rdas i <strong>Exim 4.99.3<\/strong>. Enligt utvecklarnas beskrivning garanterar patchen en ren \u00e5terst\u00e4llning av stacken f\u00f6r inmatningshantering vid mottagande av TLS close_notify under aktiv \u00f6verf\u00f6ring av BDAT, vilket f\u00f6rhindrar ytterligare anv\u00e4ndning av f\u00f6r\u00e5ldrade pekare. Inga andra k\u00e4nda s\u00e4tt att helt \u00e5tg\u00e4rda problemet, f\u00f6rutom en uppdatering, anges i rekommendationerna.<\/p>\n<p>Utvecklarna av Exim fick ett felmeddelande  <strong>den 1 maj 2026<\/strong> fr\u00e5n Federico Kirschbaum fr\u00e5n <strong>XBOW Security<\/strong>. Efter att ha granskat rapporten f\u00f6rberedde man en korrigering i slutna repositorier, den 7 maj informerades distributionerna om problemet genom en sluten mailinglista, den 10 maj gavs de begr\u00e4nsad tillg\u00e5ng till korrigeringarna, och <strong>den 12 maj 2026<\/strong> publicerades rekommendationerna och sj\u00e4lva releasen med korrigeringen.<\/p>\n<p>E-postserveradministrat\u00f6rer rekommenderas att kontrollera vilken version av Exim och TLS-backend som anv\u00e4nds. Om <a class=\"wpil_keyword_link\" href=\"https:\/\/prohoster.info\/sv\/server\/\"   title=\"server\" data-wpil-keyword-link=\"linked\">server<\/a> den k\u00f6r Exim fr\u00e5n 4.97 till 4.99.2 inklusive, kompilerad med GnuTLS och meddelar STARTTLS tillsammans med CHUNKING, rekommenderar Exim-projektet att s\u00e5 snart som m\u00f6jligt uppgradera till <strong>Exim 4.99.3<\/strong> eller en nyare version. De korrigerade k\u00e4llkoderna finns tillg\u00e4ngliga i grenen exim-4.99+fixes och taggen exim-4.99.3, samt i form av tarball-arkiv p\u00e5 vanliga Exim-nedladdningssajter.<\/p>\n<p>K\u00e4lla: <a \ncontent=\"nofollow\" rel=\"nofollow\" href=\"https:\/\/www.linux.org.ru\/news\/security\/18291306\">linux.org.ru<\/a><\/p>","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":"<p>\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 [&hellip;]<\/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<!-- All in One SEO 5.0.4 - aioseo.com -->\n\t<meta name=\"description\" content=\"\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 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korrigerande version Exim 4.99.3, som \u00e5tg\u00e4rdar en s\u00e5rbarhet i vissa konfigurationer av e-postagenten.","canonical_url":"https:\/\/prohoster.info\/sv\/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":"sv_SE","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\/sv\/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\/sv\/wp-json\/wp\/v2\/posts\/172666","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/prohoster.info\/sv\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/prohoster.info\/sv\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/prohoster.info\/sv\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/prohoster.info\/sv\/wp-json\/wp\/v2\/comments?post=172666"}],"version-history":[{"count":1,"href":"https:\/\/prohoster.info\/sv\/wp-json\/wp\/v2\/posts\/172666\/revisions"}],"predecessor-version":[{"id":173168,"href":"https:\/\/prohoster.info\/sv\/wp-json\/wp\/v2\/posts\/172666\/revisions\/173168"}],"wp:attachment":[{"href":"https:\/\/prohoster.info\/sv\/wp-json\/wp\/v2\/media?parent=172666"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/prohoster.info\/sv\/wp-json\/wp\/v2\/categories?post=172666"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/prohoster.info\/sv\/wp-json\/wp\/v2\/tags?post=172666"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}