ubuntu

Ubuntu 14.04 — fail2ban — vulnerability — patch and remediation guide — diagnosis and fix on Ubuntu 14.04

Ubuntu 14.04 — fail2ban — vulnerability — patch and remediation guide

🟢 Low   ⏱ 5–15 min  Last verified: 25 May 2026 Affected versions: Ubuntu 14.04 (trusty) 📖 ~4 min read  •  Source: Ubuntu Security Notice USN-5232-1 Related CVEs: CVE-2021-32749 Upstream summary: Jakub Żoczek discovered that certain Fail2ban actions handled whois responses in an insecure way. If Fail2ban was configured to use certain mail actions like […]

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Common Problems 118526

Ubuntu 16.04 LTS – swap not enabled after reboot

🟡 Medium   ⏱ 5–30 min  Last verified: 19 May 2026 Affected versions: Ubuntu 16.04 LTS Ubuntu 16.04 Ubuntu 16.04.7 📖 ~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 […]

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How To Set Up a Serf Cluster on Several Ubuntu VPS — step-by-step Linux tutorial on Progressive Robot

How To Set Up a Serf Cluster on Several Ubuntu VPS

Serf is a decentralized service orchestration and service discovery tool. It is extremely fault tolerant and decentralized, with no single point of failure like other similar tools. Serf can be used to trigger any event across a cluster of systems as well as perform monitoring duties. It’s built on top of the Gossip protocol which is designed for decentralized communication.

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Ubuntu 18.04 — pygments — multiple vulnerabilities (2 CVEs) — patch and remediation guide — diagnosis and fix on Ubuntu 18.04

Ubuntu 18.04 — pygments — multiple vulnerabilities (2 CVEs) — 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-4897-1 Related CVEs: CVE-2021-27291 CVE-2021-20270 Upstream summary: Ben Caller discovered that Pygments incorrectly handled parsing certain files. If a user or automated system were tricked into parsing a specially crafted […]

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Configuração Inicial de servidor com Ubuntu 18.04 — step-by-step Linux tutorial on Progressive Robot

Configuração Inicial de servidor com Ubuntu 18.04

Quando você cria inicialmente um novo servidor Ubuntu 18.04, existem alguns passos de configuração que você deve tomar no início como parte da configuração básica. Isto aumentará a segurança e a usabilidade do seu servidor e dará uma sólida fundação para as ações…

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Common Problems 115977

Ubuntu 26.04 LTS – AppArmor profile denies custom service file access – Fix & Prevention

🟡 Medium   ⏱ 5–30 min  Last verified: 19 May 2026 Affected versions: Ubuntu 26.04 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 115946

Ubuntu 26.04 LTS – SSH login fails due to incorrect permissions on ~/.ssh – Fix & Prevention

🟠 High   ⏱ 5–30 min  Last verified: 19 May 2026 Affected versions: Ubuntu 26.04 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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