A Facebook user asked how to forbid write access to an external USB drive, allowing only for read-only access. This article explains how to do that with the help of udev.
During an intrusion, an intruder leaves signs of his actions in various system logs. Without reliable logs, it could be very difficult to figure out how the attacker got in, or where the attack came from. This information is crucial in analyzing the incident. It is evident that the logs are a valuable audit trail that should be well protected.
Of course, when an intruder gets in to the system, they will try to remove all traces. So, how can we stop an intruder from removing evidence?
BREACH (Browser Reconnaissance and Exfiltration via Adaptive Compression of Hypertext) is a security exploit against HTTPS when using HTTP compression. This article shows several ways to deal with BREACH using Length Hiding technique with nginx’s builtin modules.
When using Cloudflare to hide IP address of the origin server (for example, to protect against DoS attacks), it is important to configure ACLs to allow connections to the origin server only from Cloudflare IPs. However, the list of Cloudflare IP ranges is not static, it changes over time. This post describes how to import this list into nginx automatically.
Sometimes it can be useful to get notified when someone logs into the system via SSH. This article shows several possible solutions how to configure those notifications.