Linux

Amazon Linux 2 — libwebp — multiple vulnerabilities (7 CVEs) — patch and remediation guide — diagnosis and fix on Amazon Linux 2

Amazon Linux 2 — libwebp — multiple vulnerabilities (7 CVEs) — patch and remediation guide

🟠 High   ⏱ 15–60 min  Last verified: 25 May 2026 Affected versions: Amazon Linux 2 📖 ~4 min read  •  Source: Amazon Linux advisory ALAS2-2021-1676 Related CVEs: CVE-2018-25011 CVE-2020-36328 CVE-2020-36329 CVE-2018-25013 CVE-2018-25014 CVE-2020-36330 CVE-2020-36331 Upstream summary: A flaw was found in libwebp. A heap-based buffer overflow was found in PutLE16(). The highest threat from […]

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How to Set Up Automatic Security Updates on Debian 10 — step-by-step Debian 10 tutorial on Progressive Robot

How to Set Up Automatic Security Updates on Debian 10

Introduction How to Set Up Automatic Security Updates on Debian 10 is a fundamental operation for any administrator maintaining a Debian 10 Buster server. Debian 10 Buster 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 […]

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Common Problems 115565

RHEL 7 tuned Profile Causes High Latency

🟡 Medium   ⏱ 5–30 min  Last verified: 25 February 2020 Affected versions: RHEL 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 & Hardening Related Errors & […]

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Common Problems 115498

RHEL 7 systemctl Restart Hangs Due to ExecStop Timeout

🟡 Medium   ⏱ 5–30 min  Last verified: 25 February 2020 📖 ~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 & Cross-Refs References & Further […]

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How to Configure Network Bridging on Debian 10 — step-by-step Debian 10 tutorial on Progressive Robot

How to Configure Network Bridging on Debian 10

Introduction How to Configure Network Bridging on Debian 10 is a fundamental operation for any administrator maintaining a Debian 10 Buster server. Debian 10 Buster 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 10. This […]

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How to Configure SELinux on RHEL 7 — step-by-step RHEL 7 tutorial on Progressive Robot

How to Configure SELinux on RHEL 7

How to Configure SELinux on RHEL 7 SELinux (Security-Enhanced Linux) is a mandatory access control (MAC) system built into the Linux kernel and enabled by default on every RHEL 7 installation. Unlike traditional Unix discretionary access control (DAC), which lets file owners decide who can access their files, SELinux enforces a policy defined by the […]

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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 February 2020 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) […]

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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 […]

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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 February 2020 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 […]

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