Common Problems

Common Problems 118106

Ubuntu 18.04 LTS – Nginx fails to start due to configuration syntax errors – Fix & Prevention

🟠 High   ⏱ 5–30 min  Last verified: 6 March 2021 Affected versions: Ubuntu 18.04 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 114977

Kernel Updates Installed but Old Kernel Keeps Booting

🟡 Medium   ⏱ 5–30 min  Last verified: 6 March 2021 📖 ~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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FreeBSD 12 — py35-yaml — multiple vulnerabilities (2 CVEs) — patch and remediation guide — diagnosis and fix on FreeBSD 12

FreeBSD 12 — py35-yaml — multiple vulnerabilities (2 CVEs) — patch and remediation guide

🟢 Low   ⏱ 5–15 min  Last verified: 6 March 2021 Affected versions: FreeBSD 12 📖 ~4 min read  •  Source: FreeBSD VuXML VuXML topic: py-yaml — FullLoader (still) exploitable for arbitrary command execution Related CVEs: CVE-2017-18342 CVE-2020-1747 Upstream summary: Riccardo Schirone (https://github.com/ret2libc) reports: In FullLoader python/object/new constructor, implemented by construct_python_object_apply, has support for setting […]

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Ubuntu 18.04 — shiro — multiple vulnerabilities (4 CVEs) — patch and remediation guide — diagnosis and fix on Ubuntu 18.04

Ubuntu 18.04 — shiro — multiple vulnerabilities (4 CVEs) — patch and remediation guide

🟡 Medium   ⏱ 10–30 min  Last verified: 6 March 2021 Affected versions: Ubuntu 18.04 (bionic) 📖 ~4 min read  •  Source: Ubuntu Security Notice USN-6352-1 Related CVEs: CVE-2020-13933 CVE-2020-17510 CVE-2020-11989 CVE-2020-1957 Upstream summary: It was discovered that Apache Shiro incorrectly handled certain HTTP requests. A remote attacker could possibly use this issue to bypass […]

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Oracle Linux 8 — mailman:2.1 — vulnerability — patch and remediation guide — diagnosis and fix on Oracle Linux 8

Oracle Linux 8 — mailman:2.1 — vulnerability — patch and remediation guide (ELSA-2021-1751)

🟡 Medium   ⏱ 10–30 min  Last verified: 6 March 2021 Affected versions: Oracle Linux 8 📖 ~4 min read  •  Source: ELSA advisory ELSA-2021-1751 Related CVEs: CVE-2020-12108 CVE-2020-15011 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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Amazon Linux 2 — kernel-livepatch-4.14.225-168.357 — vulnerability — patch and remediation guide — diagnosis and fix on Amazon Linux 2

Amazon Linux 2 — kernel-livepatch-4.14.225-168.357 — vulnerability — 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 ALAS2LIVEPATCH-2021-050 Related CVEs: CVE-2021-33034 Upstream summary: A use-after-free flaw was found in hci_send_acl in the bluetooth host controller interface (HCI) in Linux kernel, where a local attacker with an access […]

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Oracle Linux 8 — Unbreakable Enterprise kernel-container — vulnerability — patch and remediation guide — diagnosis and fix on Oracle Linux 8

Oracle Linux 8 — Unbreakable Enterprise kernel-container — vulnerability — patch and remediation guide (ELSA-2021-9086)

🟠 High   ⏱ 15–60 min  Last verified: 6 March 2021 Affected versions: Oracle Linux 8 📖 ~4 min read  •  Source: ELSA advisory ELSA-2021-9086 Related CVEs: CVE-2021-26932 CVE-2021-26930 CVE-2020-0431 CVE-2020-16120 CVE-2021-3347 CVE-2021-3348 Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution – Primary Fix Solution – […]

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Oracle Linux 8 — e2fsprogs — security and stability fixes — required update — diagnosis and fix on Oracle Linux 8

Oracle Linux 8 — e2fsprogs — security and stability fixes — required update (ELSA-2022-7720)

🟡 Medium   ⏱ 10–30 min  Last verified: 5 March 2021 Affected versions: Oracle Linux 8 📖 ~4 min read  •  Source: ELSA advisory ELSA-2022-7720 Related CVEs: CVE-2022-1304 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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Common Problems 118617

Ubuntu 16.04 LTS snapd Refresh Fails with Certificate Errors

🟡 Medium   ⏱ 5–30 min  Last verified: 5 March 2021 Affected versions: 16.04 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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FreeBSD 12 — syncthing — vulnerability — patch and remediation guide — diagnosis and fix on FreeBSD 12

FreeBSD 12 — syncthing — vulnerability — patch and remediation guide

🟢 Low   ⏱ 5–15 min  Last verified: 5 March 2021 Affected versions: FreeBSD 12 📖 ~4 min read  •  Source: FreeBSD VuXML VuXML topic: syncthing — crash due to malformed relay protocol message Related CVEs: CVE-2021-21404 Upstream summary: syncthing developers report: syncthing can be caused to crash and exit if sent a malformed relay […]

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