ignore_invalid_headers
The `ignore_invalid_headers` directive controls whether NGINX should ignore invalid headers in HTTP requests.
Description
The ignore_invalid_headers directive is a configuration option in NGINX that allows administrators to manage how the server handles invalid HTTP headers received in requests. When set to 'on', NGINX will ignore any invalid headers instead of rejecting the request outright. This can be useful in scenarios where the client might send malformed headers that do not conform to HTTP specifications, allowing better recovery from such errors without discarding the entire request.
The directive accepts a flag argument, either 'on' or 'off'. If set to 'on', the server will process the request normally even if it contains invalid headers. Conversely, if set to 'off', which is the default behavior, the server will reject the request and return an error response when invalid headers are encountered. This setting is applicable in both the HTTP block and within server contexts, allowing flexibility in how individual server instances can handle requests with potentially problematic headers.
Config Example
http {
ignore_invalid_headers on;
server {
listen 80;
location / {
proxy_pass http://backend;
}
}
}Setting this directive to 'on' can lead to potential security risks if invalid headers can be maliciously crafted to exploit application vulnerabilities.
Always test your application thoroughly when changing this setting, as ignoring invalid headers may result in unexpected behavior or application errors.