{"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\/da\/blog\/news\/v-exim-4-99-3-ustranena-uyazvimost-pozvolyayushhaya-udalyonnoe-vypolnenie-koda-pri-ispolzovanii-gnutls","title":{"rendered":"I Exim 4.99.3 er en s\u00e5rbarhed blevet fjernet, som muligg\u00f8r fjernudf\u00f8relse af kode ved brug af GnuTLS.","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"

Udviklerne af mailserveren Exim har udgivet en korrektivversion Exim 4.99.3<\/strong>, der fjerner en s\u00e5rbarhed i visse konfigurationer af mailagenten. Problemet er registreret under den interne identifikator EXIM-Security-2026-05-01.1<\/strong>; i den officielle meddelelse n\u00e6vnes det ogs\u00e5 som CVE-TBD<\/strong>.<\/p>\n

S\u00e5rbarheden tilh\u00f8rer klassen Remote Use-After-Free<\/strong> og opst\u00e5r under parsing af meddelelsens krop BDAT<\/strong> ved brug af TLS over GnuTLS<\/strong>. BDAT anvendes i SMTP-udvidelsen CHUNKING<\/strong> til at overf\u00f8re meddelelsens krop i blokke. If\u00f8lge beskrivelsen fra Exim kan fejlen opst\u00e5, n\u00e5r klienten under overf\u00f8rslen af BDAT sender TLS-meddelelse close_notify f\u00f8r afslutningen af overf\u00f8rslen af kroppen og derefter tilf\u00f8jer et ekstra byte inden for den samme TCP-forbindelse.<\/p>\n

I denne sekvens kan Exim skrive data til en hukommelsesbuffer, der allerede er blevet frigivet ved afslutningen af TLS-sessionen. Dette f\u00f8rer til en hukommelsesbeskadigelse og kan potentielt udnyttes til at udf\u00f8re kode. I meddelelsen understreges det, at angriberen blot skal have mulighed for at etablere en TLS-forbindelse og bruge SMTP-udvidelsen CHUNKING \/ BDAT<\/strong>.<\/p>\n

Problemet ber\u00f8rer Exim 4.97, 4.98, 4.99, 4.99.1 og 4.99.2<\/strong>, men kun versioner, der er bygget med st\u00f8tte for GnuTLS<\/strong>. I den officielle dokumentation er dette formuleret som konfigurationer med USE_GNUTLS=yes; versioner, der bruger OpenSSL<\/strong> eller andre TLS-biblioteker, er ikke p\u00e5virket af denne s\u00e5rbarhed. Det er ogs\u00e5 angivet i Exims meddelelse, at konfigurationer, hvor STARTTLS<\/strong> og CHUNKING<\/strong>.<\/p>\n

bliver erkl\u00e6ret, er s\u00e5rbare. Exim 4.99.3<\/strong>Retten er inkluderet i<\/p>\n

. If\u00f8lge udviklernes beskrivelse sikrer opdateringen en ren nulstilling af inputbehandlingsstakken ved modtagelse af TLS close_notify under aktiv overf\u00f8rsel af BDAT, hvilket forhindrer yderligere brug af for\u00e6ldede pegeres. Ingen anden kendt metode til helt at l\u00f8se problemet, bortset fra opdatering, er givet i anbefalingerne. Udviklerne af Exim modtog en fejlrapport<\/strong> den 1. maj 2026 fra Federico Kirschbaum fra<\/strong>XBOW Security . Efter at have gennemg\u00e5et rapporten blev rettelsen forberedt i lukkede repositories, den 7. maj blev distributionerne underrettet om problemet via en lukket mailingliste, den 10. maj fik de begr\u00e6nset adgang til rettelserne, og<\/strong> den 12. maj 2026<\/p>\n

blev anbefalingerne og selve rettelsen offentliggjort. Administrationspersonalet for mailservere opfordres til at kontrollere den version af Exim og TLS-backend, der anvendes. server<\/a> arbejder p\u00e5 Exim fra 4.97 til 4.99.2 inkluderet, samlet med GnuTLS og annoncerer STARTTLS sammen med CHUNKING, projektet Exim anbefaler at opgradere s\u00e5 hurtigt som muligt til Exim 4.99.3<\/strong> eller en nyere version. De rettede kildekoder er tilg\u00e6ngelige i exim-4.99+fixes grenen og exim-4.99.3 tagget, samt i form af tarball-arkiver p\u00e5 de almindelige downloadplatforme for Exim.<\/p>\n

Kilde: 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\udd47I Exim 4.99.3 er en s\u00e5rbarhed, der muligg\u00f8r fjernudf\u00f8relse af kode ved brug af GnuTLS, blevet afhjulpet | ProHoster","description":"Udviklerne af mailserveren Exim har udgivet en korrektionsversion Exim 4.99.3, der fjerner s\u00e5rbarheden i nogle konfigurationer af mailagenten.","canonical_url":"https:\/\/prohoster.info\/da\/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":"da_DK","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\/da\/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\/da\/wp-json\/wp\/v2\/posts\/172666","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/prohoster.info\/da\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/prohoster.info\/da\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/prohoster.info\/da\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/prohoster.info\/da\/wp-json\/wp\/v2\/comments?post=172666"}],"version-history":[{"count":1,"href":"https:\/\/prohoster.info\/da\/wp-json\/wp\/v2\/posts\/172666\/revisions"}],"predecessor-version":[{"id":173168,"href":"https:\/\/prohoster.info\/da\/wp-json\/wp\/v2\/posts\/172666\/revisions\/173168"}],"wp:attachment":[{"href":"https:\/\/prohoster.info\/da\/wp-json\/wp\/v2\/media?parent=172666"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/prohoster.info\/da\/wp-json\/wp\/v2\/categories?post=172666"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/prohoster.info\/da\/wp-json\/wp\/v2\/tags?post=172666"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}