{"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\/pt\/blog\/news\/v-exim-4-99-3-ustranena-uyazvimost-pozvolyayushhaya-udalyonnoe-vypolnenie-koda-pri-ispolzovanii-gnutls","title":{"rendered":"No Exim 4.99.3 foi corrigida uma vulnerabilidade que permite a execu\u00e7\u00e3o remota de c\u00f3digo ao usar GnuTLS","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"

Os desenvolvedores do servidor de email Exim lan\u00e7aram uma vers\u00e3o de corre\u00e7\u00e3o Exim 4.99.3<\/strong>, que corrige uma vulnerabilidade em algumas configura\u00e7\u00f5es do agente de email. O problema possui o identificador interno EXIM-Security-2026-05-01.1<\/strong>; na notifica\u00e7\u00e3o oficial tamb\u00e9m \u00e9 referido como CVE-TBD<\/strong>.<\/p>\n

A vulnerabilidade se enquadra na classe Uso Remoto Ap\u00f3s Libera\u00e7\u00e3o<\/strong> e se manifesta durante a an\u00e1lise do corpo da mensagem BDAT<\/strong> ao trabalhar com TLS atrav\u00e9s de GnuTLS<\/strong>. BDAT \u00e9 utilizado na extens\u00e3o SMTP CHUNKING<\/strong> para transmitir o corpo do email em blocos. Segundo a descri\u00e7\u00e3o do Exim, o erro pode ser causado quando o cliente, durante a transmiss\u00e3o do BDAT, envia a notifica\u00e7\u00e3o TLS close_notify antes da conclus\u00e3o da transmiss\u00e3o do corpo e, em seguida, adiciona um byte adicional dentro da mesma conex\u00e3o TCP.<\/p>\n

Nessa sequ\u00eancia, o Exim pode gravar dados em um buffer de mem\u00f3ria que j\u00e1 foi liberado ao encerrar a sess\u00e3o TLS. Isso leva \u00e0 corrup\u00e7\u00e3o do heap e pode potencialmente ser explorado para execu\u00e7\u00e3o de c\u00f3digo. A notifica\u00e7\u00e3o destaca que o atacante s\u00f3 precisa ser capaz de estabelecer uma conex\u00e3o TLS e usar a extens\u00e3o SMTP CHUNKING \/ BDAT<\/strong>.<\/p>\n

O problema afeta Exim 4.97, 4.98, 4.99, 4.99.1 e 4.99.2<\/strong>, mas apenas as compila\u00e7\u00f5es que foram feitas com suporte GnuTLS<\/strong>. Na documenta\u00e7\u00e3o oficial, isso \u00e9 formulado como configura\u00e7\u00f5es com USE_GNUTLS=yes; compila\u00e7\u00f5es que utilizam OpenSSL<\/strong> ou outras bibliotecas TLS n\u00e3o s\u00e3o afetadas por essa vulnerabilidade. A notifica\u00e7\u00e3o do Exim tamb\u00e9m menciona separadamente que configura\u00e7\u00f5es onde s\u00e3o declaradas STARTTLS<\/strong> e CHUNKING<\/strong>.<\/p>\n

A corre\u00e7\u00e3o est\u00e1 inclu\u00edda em Exim 4.99.3<\/strong>. Segundo os desenvolvedores, o patch garante uma limpeza completa da pilha de processamento de entrada ao receber um TLS close_notify durante a transmiss\u00e3o ativa do BDAT, o que impede o uso de ponteiros obsoletos. N\u00e3o h\u00e1 outra maneira conhecida de fechar completamente o problema al\u00e9m da atualiza\u00e7\u00e3o.<\/p>\n

Os desenvolvedores do Exim receberam o relat\u00f3rio de bug em 1\u00ba de maio de 2026<\/strong> de Federico Kirschbaum da XBOW Security<\/strong>. Ap\u00f3s a verifica\u00e7\u00e3o do relat\u00f3rio, a corre\u00e7\u00e3o foi desenvolvida em reposit\u00f3rios privados, no dia 7 de maio, a quest\u00e3o foi comunicada aos distribui\u00e7\u00f5es atrav\u00e9s de uma lista de discuss\u00e3o privada, no dia 10 de maio, foi fornecido acesso limitado \u00e0s corre\u00e7\u00f5es, e em 12 de maio de 2026<\/strong> as recomenda\u00e7\u00f5es e a pr\u00f3pria vers\u00e3o com a corre\u00e7\u00e3o foram publicadas.<\/p>\n

Os administradores de servidores de e-mail s\u00e3o aconselhados a verificar a vers\u00e3o do Exim e o backend TLS utilizado. Se servidor<\/a> estiver rodando a vers\u00e3o do Exim de 4.97 at\u00e9 4.99.2 inclusive, compilado com GnuTLS e anunciando STARTTLS juntamente com CHUNKING, o projeto Exim recomenda que a atualiza\u00e7\u00e3o para Exim 4.99.3<\/strong> uma vers\u00e3o mais recente seja feita o mais r\u00e1pido poss\u00edvel. Os c\u00f3digos-fonte corrigidos est\u00e3o dispon\u00edveis na branch exim-4.99+fixes e na tag exim-4.99.3, bem como em arquivos tarball nos reposit\u00f3rios de download do Exim.<\/p>\n

Fonte: 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\udd47Na vers\u00e3o Exim 4.99.3 foi corrigida uma vulnerabilidade que permite a execu\u00e7\u00e3o remota de c\u00f3digo ao utilizar GnuTLS | ProHoster","description":"Os desenvolvedores do servidor de e-mail Exim lan\u00e7aram uma vers\u00e3o de corre\u00e7\u00e3o do Exim 4.99.3, que resolve uma vulnerabilidade em algumas configura\u00e7\u00f5es do agente de correio.","canonical_url":"https:\/\/prohoster.info\/pt\/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":"pt_PT","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\/pt\/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\/pt\/wp-json\/wp\/v2\/posts\/172666","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/prohoster.info\/pt\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/prohoster.info\/pt\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/prohoster.info\/pt\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/prohoster.info\/pt\/wp-json\/wp\/v2\/comments?post=172666"}],"version-history":[{"count":1,"href":"https:\/\/prohoster.info\/pt\/wp-json\/wp\/v2\/posts\/172666\/revisions"}],"predecessor-version":[{"id":173168,"href":"https:\/\/prohoster.info\/pt\/wp-json\/wp\/v2\/posts\/172666\/revisions\/173168"}],"wp:attachment":[{"href":"https:\/\/prohoster.info\/pt\/wp-json\/wp\/v2\/media?parent=172666"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/prohoster.info\/pt\/wp-json\/wp\/v2\/categories?post=172666"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/prohoster.info\/pt\/wp-json\/wp\/v2\/tags?post=172666"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}