Apache, receiving a request with an encoded semicolon (%3B) is decoding it before passing the request to a proxy (backend of Spring Tomcat).

Relevant apache Virtual host lines are:

ProxyPreserveHost on
RequestHeader set X-Forwarded-Proto https
ProxyPass /
ProxyPassReverse /

So for example when a request for URL like


Would be proxy forwarded as


Is there something I can do to prevent apache from decoding that URL before forwarding it to proxy?

Perhaps relevant issue noted on apache.org/bugzilla

  • 1
    Try you with nocanon directive? – Federico Sierra Sep 20 '17 at 22:21
  • @FedericoSierra Sorry. Apache noob here. What's the syntax for that directive? – Baker Sep 20 '17 at 22:24
  • 1
    Eg: ProxyPass / nocanon – Federico Sierra Sep 20 '17 at 22:26
  • @FedericoSierra Can I buy you a beer? Worked. Many thanks. – Baker Sep 20 '17 at 22:32

mod_proxy canonicalise URLs passed to the backend. If you want suppress this behavior use nocanon keyword and this passes the URL path "raw" to the backend.


ProxyPass / nocanon

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