Connection from [a.b.c.d]… refused: too many connections and Exim
At times your Exim server might be overwhelmed: 2023-11-09 12:04:05 Connection from [188.234.244.30]:3802 refused: too many connections Your server is most likely under attack. Check
Security
Fixing cURL error 77: Unable to initialize NSS: -8023 (SEC_ERROR_PKCS11_DEVICE_ERROR)
Out of the blue WordPress starts giving problems. This server has been stable for years. Clue: It’s CentOS 7. Probably time to move away. Anyhow,
SSH Cheat Sheet
How to Audit SSH The /etc/ssh/sshd_config file has many options. Fortunately in a typical environment you have to only focus on a few options to
How to disable ConfigServer Firewall on WHM’s LFD blocked emails
Background ConfigServer Firewall on WHM is incredibly noisy. To the point that you have to set up so many email rules just to be on
How to enable TLS 1.1 and TLS 1.2 on Windows 7 and deal with Outlook encryption type errors
Basically Windows 7 is end of life 2020. Some users insist on still using it or don’t want to pay for upgrades, because actually, IT
How to install a CloudFlare origin server SSL certificate into Virtualmin
Background If your Virtualmin website is using Cloudflare as a proxy you can’t use the standard Let’s Encrypt HTTP method to request a fresh certificate.
How to deal with CSP and being contacted by a “security researcher”
Background You might be approached by someone looking for money. They will give you this information (broken English included): Summary: X-Frame-Options ALLOW-FROM https://billing.example.com/login not supported
Unable to restart FirewallD – Found left-over process 1234567 (rmmod)
To restart FirewallD, use this command: service firewalld restart However, if FirewallD refuses to restart, and you check the status using this command: service firewalld
Pentest – Penetration Testing – What is it, and what tools are involved
Penetration testing is popular to check internet exploits. Here are a number of tools and services to help with checking up your security. Here is
Fail2ban stops working because FirewallD is not running
Observing the fail2ban log file shows that IPs are already banned but still appearing in the list. Closer inspection of the log file shows that