What is CVE-2023-25690 Mod Proxy Configuration?
Some mod_proxy configurations between Apache HTTP Server versions 2.4.0 and 2.4.55 may lead to an HTTP Request Smuggling attack.
Configurations are affected when mod_proxy is enabled, and a pattern in some form, such as RewriteRule or ProxyPassMatch, matches a portion of the user-supplied request-target (URL) data.
Subsequently, this matched data is re-inserted into the proxied request-target using variable substitution.
For example, something like: RewriteEngine on RewriteRule "^/here/(.*)" "http://example.com:8080/elsewhere?$1"; [P] ProxyPassReverse /here/ http://example.com:8080/ Request splitting/smuggling could result in bypassing access controls on the proxy server, directing unwanted URLs to client servers, and cache poisoning. Users are recommended to update to at least version 2.4.56 of Apache HTTP Server.
Source :https://www.turkhackteam.org/konular/cve-2023-25690-mod-proxy-yapilandirmasi-nedir.2048386/