Reverse proxy issue with Chrome

Andreas Habel <ahabel@xxxxxxxxxxxxx> · Fri, 14 May 2021 14:43:53 +0200

Hello,

since Chrome and Chrome-based browsers recently were updated to Chrome 

90 I am experiencing a 502 proxy error when I try to access my web 

servers with these browsers.

Before the update to Chrome 90 things worked fine, and everything still 

works with Firefox.

Here's my setup:

                    --> webserver1

Internet --> router/firewall --> web server with reverse proxy --> 

webserver2

  --> webserver3

When accessing any of the web servers that are behind the reverse proxy 

I get the following in the error.log of the web server that is 

configured as reverse proxy:

[Fri May 14 11:50:20.555724 2021] [proxy_http:error] [pid 1466:tid 

140450128164608] (20014)Internal error (specific information not 

available): [client 192.168.0.1:42450] AH01102: error reading status 

line from remote server 192.168.0.102:80

[Fri May 14 11:50:20.555768 2021] [proxy:error] [pid 1466:tid 

140450128164608] [client 192.168.0.1:42450] AH00898: Error reading from 

remote server returned by /

[Fri May 14 11:50:20.563497 2021] [reqtimeout:info] [pid 1467:tid 

140450442671872] [client 192.168.0.1:42452] AH01382: Request header read 

timeout

other_vhosts_access.log on web server with reverse proxy:

webserver1.com:443 192.168.0.1 - - [14/May/2021:11:50:00 +0200] "GET / 

HTTP/1.1" 502 4344 "-" "Mozilla/5.0 (X11; Linux x86_64) 

AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.93 Safari/537.36 

OPR/76.0.4017.123"

webserver2.com:443 192.168.0.1 - - [14/May/2021:11:50:20 +0200] "-" 408 

3681 "-" "-"

webserver1.com:443 192.168.0.1 - - [14/May/2021:11:50:20 +0200] "GET 

/favicon.ico HTTP/1.1" 200 24 "https://webserver1.com/"; "Mozilla/5.0 

(X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) 

Chrome/90.0.4430.93 Safari/537.36 OPR/76.0.4017.123"

access.log on webserver1:
192.168.3.11 - - [14/May/2021:11:50:20 +0200] "-" 408 0 "-" "-"

192.168.0.1 = router/firewall
192.168.3.11 = web server with reverse proxy in DMZ
192.168.0.102 = wevserver1

Here is the webserver1.conf in sites-enabled:

<IfModule mod_ssl.c>
<VirtualHost *:443>
 ServerName webserver1.com
 SSLEngine On
 SSLProxyEngine On
 ProxyPreserveHost On
 <Proxy *>
        Order deny,allow
        Allow from all
 </Proxy>
 ProxyRequests Off
 ProxyPreserveHost On
 ProxyPass /zm/ http://192.168.0.102/zm/
 ProxyPassReverse /zm/ http://192.168.0.102/zm/
 ProxyPass / http://192.168.0.102/zm/
 ProxyPassReverse / http://192.168.0.102/zm/

 DocumentRoot /var/www/html
 ProxyPass /.well-known !

 Include /etc/letsencrypt/options-ssl-apache.conf
 SSLCertificateFile /etc/letsencrypt/live/webserver1.com/fullchain.pem
 SSLCertificateKeyFile /etc/letsencrypt/live/webserver1.com/privkey.pem
</VirtualHost>
</IfModule>

Apache version on the web server with reverse proxy and on webserver1 

is: Apache/2.4.29 (Ubuntu) on Ubuntu 18.04.5

I wonder if there is anything wrong in my config? Any help is highly 

appreciated.

Best regards,

Andreas

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