Security Hardening

Common Problems 121041

SSH Login Fails with Public Key Authentication

🟠 High   ⏱ 5–30 min  Last verified: 28 October 2020 Affected versions: Debian 10 📖 ~1 min read Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution – Primary Fix Solution – Alternative Approaches Verification & Acceptance Criteria Rollback Plan Prevention & Hardening Related Errors & […]

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Common Problems 117411

Ubuntu 20.04 LTS apt Lock Contention During Auto Updates

🟡 Medium   ⏱ 5–30 min  Last verified: 28 October 2020 Affected versions: 20.04 LTS 📖 ~1 min read Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution – Primary Fix Solution – Alternative Approaches Verification & Acceptance Criteria Rollback Plan Prevention & Hardening Related Errors & […]

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Common Problems 113540

Windows Server 2012 R2 — sIDHistory cleanup needed to retire deprecated SIDs after migration — Fix & Prevention

🟠 High   ⏱ 5–30 min  Last verified: 28 October 2020 Affected versions: Windows Server 2012 R2 📖 ~2 min read Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution — Primary Fix Solution — Alternative Approaches Verification & Acceptance Criteria Rollback Plan Prevention & Hardening Related […]

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How to Set Up Port Knocking on SLES 12 — step-by-step SUSE Linux Enterprise 12 tutorial on Progressive Robot

How to Set Up Port Knocking on SLES 12

Introduction This tutorial covers How to Set Up Port Knocking on SLES 12 on SLES 12. SLES 12 (SUSE Linux Enterprise Server 16) is SUSE’s enterprise-grade Linux distribution. It uses the zypper package manager, AppArmor for mandatory access control, and systemctl for service management. Prerequisites Ensure your SLES 12 system is up to date: zypper […]

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FreeBSD 12 — payara — multiple vulnerabilities (15 CVEs) — patch and remediation guide — diagnosis and fix on FreeBSD 12

FreeBSD 12 — payara — multiple vulnerabilities (15 CVEs) — patch and remediation guide

🟠 High   ⏱ 15–60 min  Last verified: 28 October 2020 Affected versions: FreeBSD 12 📖 ~4 min read  •  Source: FreeBSD VuXML VuXML topic: Payara — path trasversal flaw via either loc/con parameters in Eclipse Mojarra Related CVEs: CVE-2016-1000031 CVE-2016-5528 CVE-2017-12615 CVE-2017-3239 CVE-2017-3247 CVE-2017-3249 CVE-2017-3250 CVE-2018-14371  +7 more Upstream summary: Payara Releases reports: The […]

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How to Install Netdata on Oracle Linux 8 — step-by-step Oracle Linux 8 tutorial on Progressive Robot

How to Install Netdata on Oracle Linux 8

Introduction How to Install Netdata on Oracle Linux 8 on Oracle Linux 8 provides administrators with a robust, enterprise-ready workflow that integrates cleanly with systemd, SELinux, firewalld, and the modern AppStream module system. In this tutorial we will walk through every step required, from package installation to verification, so that the resulting configuration is reproducible […]

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Oracle Linux 8 — varnish:6 security, bug fix, and — enhancement update — new behaviour and fixes — diagnosis and fix on Oracle Linux 8

Oracle Linux 8 — varnish:6 security, bug fix, and — enhancement update — new behaviour and fixes (ELSA-2020-4756)

🟡 Medium   ⏱ 10–30 min  Last verified: 27 October 2020 Affected versions: Oracle Linux 8 📖 ~4 min read  •  Source: ELSA advisory ELSA-2020-4756 Related CVEs: CVE-2019-20637 CVE-2019-15892 CVE-2020-11653 Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution – Primary Fix Solution – Alternative Approaches Verification […]

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Common Problems 121593

Debian 9: PostgreSQL fails because WAL partition is full

🔴 Critical   ⏱ 5–30 min  Last verified: 27 October 2020 Affected versions: Debian 9 📖 ~1 min read Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution – Primary Fix Solution – Alternative Approaches Verification & Acceptance Criteria Rollback Plan Prevention & Hardening Related Errors & […]

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Common Problems 121474

Debian 9 – apt update shows NO_PUBKEY and rejects repository signatures

🟠 High   ⏱ 5–30 min  Last verified: 27 October 2020 Affected versions: Debian 9 📖 ~1 min read Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution – Primary Fix Solution – Alternative Approaches Verification & Acceptance Criteria Rollback Plan Prevention & Hardening Related Errors & […]

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How to Set Up the ELK Stack on Oracle Linux 8 — step-by-step Oracle Linux 8 tutorial on Progressive Robot

How to Set Up the ELK Stack on Oracle Linux 8

Introduction This tutorial demonstrates how to Set Up the ELK Stack on Oracle Linux 8 on Oracle Linux 8. It is written for administrators who want a repeatable, well-explained walkthrough that goes beyond a bare command list and explains each configuration choice. Every command is tested against a freshly registered Oracle Linux 8 system with […]

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