DNS issue crash sites

  • Resolved tezalsec

    (@tezalsec)


    2 weeks, 3 days ago

    Hi, after having used the Brevo plugin for two years happily without much problems, I now encountered a serious and frustrating issue. It has caused me many hours to find the cause was the Brevo plugin. As DNS issues can be very diverse, at first I blamed the internet connection, the ISP, my VPS, the application firewall, windows DNS cache, browser DNS cache, etc.. Until I decided to just check all my WP plugins, one by one. And found out it was your plugin causing the crashes!

    Any idea how your plugin works with or affects a WP site’s relation to DNS? With your plugin activated after a few pageloads I consistently get ERR CONNECTION TIME OUT errors, coupled to DNS. It is NOT a memory thing, because when I change my visiting IP address, it loads again fine, until after a few pageloads, then it crashes again. On any page within WP, not just Brevo’s admin page.

    Please help me out here. Thanks.

Viewing 5 replies - 1 through 5 (of 5 total)
  • Thread Starter tezalsec

    (@tezalsec)

    No response, guys? I hope you can help me out here.

    I tested further by rolling back versions up to 3.1.83, but they all had the same issue. I do not know how to debug this further. The only thing really helping so far is turning off your plugin…

    Plugin Support alexisbienayme

    (@alexisbienayme)

    Hello @tezalsec,

    Apologies for the late answer.

    Could you please open a ticket at https://account.Brevo.com/support ? Your problem may require the intervention of our technicians.

    Best Regards,

    Alexis

    Thread Starter tezalsec

    (@tezalsec)

    For the sake of completeness, I’ll share here that I found the cause of the issue.

    Your use of an ico file in the admin menu triggered a “client denied by server configuration” rule in the fail2ban software on the server. Explaining the “DNS issue”…, since my IP just gets banned after a few pageloads in the backend.

    Entry causing it:? [Tue Nov 19 14:40:20.005635 2024] [access_compat:error] [pid 1977:tid 140082321266240] [client xxx:0] AH01797: client denied by server configuration: /var/www/vhosts/xxx/httpdocs/wp-content/plugins/mailin/img/favicon.ico

    Fortunately the image file only loads in the backend and not in the frontend, otherwise all visitors would be banned.

    I have noticed this log entry for a long time, apparently my server, using DEFAULT apache rules, is not happy with your use of an ico file here. But it never caused any problems, until recently. All other wordpress plugins use png, svg, etc.. for their admin menu image files and they do not trigger same errors. Maybe it is an idea for you at Brevo to change the .ico extension into .png ? I am sure it will make many users happy, and may also speed up loading time in the backend and create less error logs.

    So hereby a request to the developers: change the ico file into a png file in the admin menu to become more in line with other plugins and cause less errors.

    Added: I noticed the file is already an actual png file, just posing as ico extension, causing a mimetype error. WordPress rejects this practice, explaining why it is not shown in the menu.

    Plugin Support fbrevo

    (@fbrevo)

    Hello @tezalsec

    Thank you for this information.

    For us to be able to make a structured and complete response, we need to receive a written request as requested by my colleague in the previous message.

    This will enable us to attach personalized information to your request and provide you with the appropriate support.

    In your written request, you can copy/paste your messages or even just allude to this conversation by providing the name of the request “DNS issue crash sites” and the URL https://www.ads-software.com/support/topic/dns-issue-crash-sites/. We’ll also need the Support ID of your Brevo account.

    Thank you very much for your cooperation, your feedback is greatly appreciated.

    Thread Starter tezalsec

    (@tezalsec)

    Hi @fbrevo , thanks for responding, but there was no need, I had already initiated the support request as suggested. I just wanted to close this topic explaining the cause of the issue.

Viewing 5 replies - 1 through 5 (of 5 total)
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