Apache Log4J Core
Monthly
Man-in-the-middle attacks are possible in Apache Log4j Core through 2.25.3 when SMTP, Socket, or Syslog appenders use TLS with the verifyHostName attribute configured in the <Ssl> element, because the attribute was silently ignored despite being available since version 2.12.0. This is a regression from an incomplete fix to CVE-2025-68161 that only addressed hostname verification via system property. An attacker with a certificate from a trusted CA can intercept TLS connections. Apache has released patched version 2.25.4 to correct this issue.
Man-in-the-middle attacks are possible in Apache Log4j Core through 2.25.3 when SMTP, Socket, or Syslog appenders use TLS with the verifyHostName attribute configured in the <Ssl> element, because the attribute was silently ignored despite being available since version 2.12.0. This is a regression from an incomplete fix to CVE-2025-68161 that only addressed hostname verification via system property. An attacker with a certificate from a trusted CA can intercept TLS connections. Apache has released patched version 2.25.4 to correct this issue.