Fix ConflictingHeadersException on generic reverse-proxy hosting#16
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back-2-95 wants to merge 1 commit into
Open
Fix ConflictingHeadersException on generic reverse-proxy hosting#16back-2-95 wants to merge 1 commit into
back-2-95 wants to merge 1 commit into
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The auto-detect branch trusted both the "Forwarded" header and the individual "X-Forwarded-*" headers at once, which Symfony explicitly disallows. Proxies like Traefik only send X-Forwarded-*, so any client sending its own "Forwarded" header straight through the proxy causes Request::getTrustedValues() to throw when the two disagree. Drop HEADER_FORWARDED from the trusted set to match what these proxies actually send.
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Summary
Reader.php(used when no known hosting system is detected, e.g. our own Traefik-fronted UpCloud hosts),reverse_proxy_trusted_headerstrusted bothRequest::HEADER_FORWARDEDand the individualRequest::HEADER_X_FORWARDED_*headers at the same time.Request::getTrustedValues()throwsConflictingHeadersExceptionwhenever a request carries both a trustedForwardedheader and a trustedX-Forwarded-*header whose derived values disagree.X-Forwarded-*headers, neverForwarded. Since Traefik doesn't restrict which client IPs it trusts to set forwarding headers (noforwardedHeaders.trustedIPs), any external client can send its ownForwardedheader straight through. Because Drupal trusted both header types, a mismatching client-suppliedForwardedheader crashed the request.ConflictingHeadersExceptionon essentially every request from clients sending aForwardedheader.Fix
Drop
Request::HEADER_FORWARDEDfrom the trusted header bitmask in the auto-detect branch, since it's never actually the header format these proxies use.Test plan
php -l src/Reader.phpmake test)