Debian 10 DLA-3401-1 Critical: Apache2 HTTP Request Smuggling Advisory

Unfortunately, fixing these security vulnerabilities may require
changes to configuration files. Some out-of-specification
RewriteRule directives that were previously silently accepted,
are now rejected with error AH10409. For instance, some RewriteRules
that included a back-reference and the flags "[L,NC]" will need to
be written with extra escaping flags such as "[B= ?,BNP,QSA]".

CVE-2023-25690

Some mod_proxy configurations allow an HTTP request Smuggling
attack. Configurations are affected when mod_proxy is
enabled along with some form of RewriteRule
or ProxyPassMatch in which a non-specific pattern matches
some portion of the user-supplied request-target (URL)
data and is then re-inserted into the proxied request-target
using variable substitution.

CVE-2023-27522

HTTP Response Smuggling in mod_proxy_uwsgi

For Debian 10 buster, these problems have been fixed in version
2.4.38-3+deb10u10.

We recommend that you upgrade your apache2 packages.