February 2020 - Page 11 of 64

Random Number Generator in Java — step-by-step Programming tutorial on Progressive Robot

Random Number Generator in Java

URL: https://www.progressiverobot.com/random-number-generator-java/ Today we will look at how to generate a random number in Java. Sometimes we need to generate random numbers in Java programs. For example, a dice game or to generate a random key id for encryption, etc. Random Number Generator in Java !random number generator java There are many ways to generate […]

Read more
Ubuntu 16.04 — sa-exim — vulnerability — patch and remediation guide — diagnosis and fix on Ubuntu 16.04

Ubuntu 16.04 — sa-exim — vulnerability — patch and remediation guide

🟢 Low   ⏱ 5–15 min  Last verified: 25 May 2026 Affected versions: Ubuntu 16.04 (xenial) 📖 ~4 min read  •  Source: Ubuntu Security Notice USN-4520-1 Related CVEs: CVE-2019-19920 Upstream summary: It was discovered that Exim SpamAssassin does not properly handle configuration strings. An attacker could possibly use this issue to execute arbitrary code. (CVE-2019-19920) […]

Read more
How to Set Up Port Knocking for SSH on RHEL 8 — step-by-step RHEL 8 tutorial on Progressive Robot

How to Set Up Port Knocking for SSH on RHEL 8

Port knocking is a stealthy technique that keeps SSH’s port 22 invisible to network scanners until a client sends a precise sequence of connection attempts to predetermined ports. On RHEL 8, combining knockd with firewalld creates a powerful two-layer defense: the firewall silently drops all traffic on port 22 by default, and only the knock […]

Read more
Oracle Linux 8 — git — vulnerability — patch and remediation guide — diagnosis and fix on Oracle Linux 8

Oracle Linux 8 — git — vulnerability — patch and remediation guide (ELSA-2020-1513)

🟠 High   ⏱ 15–60 min  Last verified: 25 May 2026 Affected versions: Oracle Linux 8 📖 ~4 min read  •  Source: ELSA advisory ELSA-2020-1513 Related CVEs: CVE-2020-5260 Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution – Primary Fix Solution – Alternative Approaches Verification & Acceptance […]

Read more
How To Build a Custom Terraform Module — step-by-step Devops tutorial on Progressive Robot

How To Build a Custom Terraform Module

Terraform modules encapsulate distinct logical components of your infrastructure by grouping their resources together. In this tutorial, you’ll create a Terraform module that will set up multiple Droplets behind a Load Balancer for redundancy. You’ll also use the for_each and count looping features of the Hashicorp Configuration Language (HCL) to deploy multiple customized instances of the module at the same time.

Read more
Basic Animations in Flutter — step-by-step DevOps tutorial on Progressive Robot

Basic Animations in Flutter

Learn how to create basic effects using Flutter’s built in controller API. You’ll learn about linear animations, curved animations, tweens and cross screens.

Read more
CHAT