CVE-2025-46551

JRuby-OpenSSL is an add-on gem for JRuby that emulates the Ruby OpenSSL native library. Starting in JRuby-OpenSSL version 0.12.1 and prior to version 0.15.4 (corresponding to JRuby versions starting in 9.3.4.0 prior to 9.4.12.1 and 10.0.0.0 prior to 10.0.0.1), when verifying SSL certificates, JRuby-OpenSSL does not verify that the hostname presented in the certificate matches the one the user tries to connect to. This means a man-in-the-middle could just present any valid cert for a completely different domain they own, and JRuby would accept the cert. Anybody using JRuby to make requests of external APIs, or scraping the web, that depends on https to connect securely. JRuby-OpenSSL version 0.15.4 contains a fix for the issue. This fix is included in JRuby versions 10.0.0.1 and 9.4.12.1.

JRuby-OpenSSL is an add-on gem for JRuby that emulates the Ruby OpenSSL native library. Starting in JRuby-OpenSSL version 0.12.1 and prior to version 0.15.4 (corresponding to JRuby versions starting in 9.3.4.0 prior to 9.4.12.1 and 10.0.0.0 prior to 10.0.0.1), when verifying SSL certificates, JRuby-OpenSSL does not verify that the hostname presented in the certificate matches the one the user tries to connect to. This means a man-in-the-middle could just present any valid cert for a completely different domain they own, and JRuby would accept the cert. Anybody using JRuby to make requests of external APIs, or scraping the web, that depends on https to connect securely. JRuby-OpenSSL version 0.15.4 contains a fix for the issue. This fix is included in JRuby versions 10.0.0.1 and 9.4.12.1.

### Summary When verifying SSL certificates, jruby-openssl is not verifying that the hostname presented in the certificate matches the one we are trying to connect to, meaning a MITM could just present _any_ valid cert for a completely different domain they own, and JRuby wouldn't complain. ### Details n/a ### PoC An example domain bad.substitutealert.com was created to present the a certificate for the domain s8a.me. The following script run in IRB in CRuby 3.4.3 will fail with `certificate verify failed (hostname mismatch)`, but will work just fine in JRuby 10.0.0.0 and JRuby 9.4.2.0, both of which use jruby-openssl version 0.15.3 ```ruby require "net/http" require "openssl" uri = URI("https://bad.substitutealert.com/") https = Net::HTTP.new(uri.host, uri.port) https.use_ssl = true https.verify_mode = OpenSSL::SSL::VERIFY_PEER body = https.start { https.get(uri.request_uri).body } puts body ``` ### Impact Anybody using JRuby to make requests of external APIs, or scraping the web, that depends on https to connect securely

### Summary When verifying SSL certificates, jruby-openssl is not verifying that the hostname presented in the certificate matches the one we are trying to connect to, meaning a MITM could just present _any_ valid cert for a completely different domain they own, and JRuby wouldn't complain. ### Details n/a ### PoC An example domain bad.substitutealert.com was created to present the a certificate for the domain s8a.me. The following script run in IRB in CRuby 3.4.3 will fail with `certificate verify failed (hostname mismatch)`, but will work just fine in JRuby 10.0.0.0 and JRuby 9.4.2.0, both of which use jruby-openssl version 0.15.3 ```ruby require "net/http" require "openssl" uri = URI("https://bad.substitutealert.com/") https = Net::HTTP.new(uri.host, uri.port) https.use_ssl = true https.verify_mode = OpenSSL::SSL::VERIFY_PEER body = https.start { https.get(uri.request_uri).body } puts body ``` ### Impact Anybody using JRuby to make requests of external APIs, or scraping the web, that depends on https to connect securely

JRuby-OpenSSL es una gema complementaria para JRuby que emula la librería nativa Ruby OpenSSL. A partir de la versión 0.12.1 de JRuby-OpenSSL y anteriores a la 0.15.4 (correspondientes a las versiones de JRuby 9.3.4.0 anteriores a la 9.4.12.1 y 10.0.0.0 anteriores a la 10.0.0.1), al verificar certificados SSL, JRuby-OpenSSL no verifica que el nombre de host presentado en el certificado coincida con el del usuario al que intenta conectarse. Esto significa que un intermediario podría presentar cualquier certificado válido para un dominio completamente diferente al suyo, y JRuby lo aceptaría. Cualquiera que use JRuby para realizar solicitudes a API externas o para rastrear datos web que dependan de https para conectarse de forma segura. La versión 0.15.4 de JRuby-OpenSSL contiene una solución para este problema. Esta corrección está incluida en las versiones 10.0.0.1 y 9.4.12.1 de JRuby.