Use Netcat to Establish and Test TCP and UDP Connections: A Practical Guide
Learn how to use Netcat to test TCP and UDP connections for troubleshooting and network diagnostics. Includes key commands, examples, and common use cases.
FreeBSD 12 — gnats — vulnerability — patch and remediation guide
🟢 Low ⏱ 5–15 min Last verified: 25 May 2026 Affected versions: FreeBSD 12 📖 ~4 min read • Source: FreeBSD VuXML VuXML topic: gnats — format string vulnerability Related CVEs: CVE-2004-0623 Upstream summary: Gnats suffers from a format string bug, which may enable an attacker to execute arbitary code. Table of contents Symptom […]
Debian 10 — libidn2 — vulnerability — patch and remediation guide
🟢 Low ⏱ 5–15 min Last verified: 25 May 2026 Affected versions: Debian 10 (buster) 📖 ~4 min read • Source: Debian Security Tracker Related CVEs: CVE-2019-18224 Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution – Primary Fix Solution – Alternative Approaches Verification & Acceptance […]
How To Create a SSL Certificate on Apache for Debian 8
This tutorial walks you through the setup and configuration of an Apache server secured with an SSL certificate. By the end of the tutorial, you will have a server accessible via HTTPS.
How to Install Puppet Agent on Debian 9
Introduction How to Install Puppet Agent on Debian 9 is a fundamental operation for any administrator maintaining a Debian 9 Stretch server. Debian 9 Stretch ships with the Linux 6.12 kernel, updated toolchains, and a fully refreshed package archive — meaning version numbers, configuration file paths, and some dependency chains differ from Debian 9. This […]
Ubuntu 18.04 — xmltooling — vulnerability — patch and remediation guide
🟢 Low ⏱ 5–15 min Last verified: 25 May 2026 Affected versions: Ubuntu 18.04 (bionic) 📖 ~4 min read • Source: Ubuntu Security Notice USN-3921-1 Related CVEs: CVE-2019-9628 Upstream summary: It was discovered that XMLTooling incorrectly handled certain XML files with invalid data. An attacker could use this issue to cause XMLTooling to crash, […]
Debian 9 — dovecot — multiple vulnerabilities (4 CVEs) — patch and remediation guide
🟡 Medium ⏱ 10–30 min Last verified: 25 May 2026 Affected versions: Debian 9 (stretch) 📖 ~4 min read • Source: Debian Security Tracker Related CVEs: CVE-2017-14461 CVE-2019-11500 CVE-2019-3814 CVE-2019-7524 Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution – Primary Fix Solution – Alternative Approaches […]
Comparable and Comparator in Java Example
Comparable and Comparator in Java are very useful for sorting the collection of objects. Java provides some inbuilt methods to sort primitive types array or Wrapper classes array or list. Here we will first learn how we can sort an array/list of primitive types and wrapper classes and then we will use java.lang.Comparable and java.util.Comparator […]
Built-in Pipes in Angular
Learn about the built-in pipes available in Angular 2+: async, currency, decimal, date, json, percent, slide, lowercase & uppercase.
How to Install Java on Ubuntu: JRE, JDK, OpenJDK & Oracle Guide (2025)
In 2025, installing Java on Ubuntu remains essential for running applications like Tomcat, Jetty, Glassfish, Cassandra, and Jenkins. The Java Virtual Machine (JVM) powers these tools, and Ubuntu’s apt makes setup straightforward for both Java Runtime Environment (JRE) and Java Development Kit (JDK). This step-by-step how to install Java on Ubuntu guide covers OpenJDK (default, open-source) and Oracle JDK installations, managing multiple versions, setting JAVA_HOME, troubleshooting, and best practices. Whether you’re a developer or sysadmin, follow these instructions for a seamless setup on Ubuntu 22.04+.
