https://bz.apache.org/bugzilla/show_bug.cgi?id=65641
--- Comment #1 from apa...@ophion.ch --- We're seeing this error as well, albeit on a slightly different version (details below). I'm not 100% sure it's related, but it looks like it to me. First, we have the following in the error.log, it looks like an attack from this client IP (which is also listed as malicious): [Mon Jan 31 01:45:59.780187 2022] [proxy:warn] [pid 4248:tid 139664061830912] [client 185.180.143.138:37166] AH01144: No protocol handler was valid for the URL / (scheme 'https'). If you are using a DSO version of mod_proxy, make sure the proxy submodules are included in the configuration using LoadModule., referer: http:/?unix:| Note the "?unix:|" at the end. From this moment on, the backend is unreachable: [Mon Jan 31 06:21:10.444950 2022] [proxy:error] [pid 4247:tid 139663763281664] (13)Permission denied: AH02454: HTTPS: attempt to connect to Unix domain socket /var/run/apache2/ (<URL_REMOVED>) failed [Mon Jan 31 06:21:10.444998 2022] [proxy_http:error] [pid 4247:tid 139663763281664] [client <IP_REMOVED>:46136] AH01114: HTTP: failed to make connection to backend: httpd-UDS Apache is on 2.4.38-3+deb10u4. We've now updated to 2.4.38-3+deb10u7 on one system and see if behaviour changes. -- You are receiving this mail because: You are the assignee for the bug. --------------------------------------------------------------------- To unsubscribe, e-mail: bugs-unsubscr...@httpd.apache.org For additional commands, e-mail: bugs-h...@httpd.apache.org