[fastcgi] environment variable overwrites HTTP_*
#996
Merged
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
In current implementation, environment variables set using
setenv
configuration directive does not overwrite the received HTTP request headers. The bug makes us impossible to use the directive to block attacks trying to exploit httpoxy vulnerability.This PR is a quick fix for the issue so that we can use the directive to prevent the attack.
Note that there are other issues in how we build FastCGI request parameters:
setenv
cannot cannot rewrite specially-treated headers likeHTTP_HOST
unsetenv
cannot be used for resettingHTTP_*
, etc.So we might fix all these issues at once, depending on how long it would take.
relates to #994