July 2021 - Page 10 of 69

Common Problems 121623

Debian 9: UFW blocks required application ports

🟡 Medium   ⏱ 5–30 min  Last verified: 20 May 2026 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 118981

Ubuntu 14.04 LTS SSH login fails with permission denied

🟠 High   ⏱ 5–30 min  Last verified: 19 May 2026 Affected versions: 14.04 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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Arch Linux — nvidia-utils — multiple vulnerabilities (6 CVEs) — patch and remediation guide — diagnosis and fix on Arch Linux

Arch Linux — nvidia-utils — multiple vulnerabilities (6 CVEs) — patch and remediation guide

🟠 High   ⏱ 15–60 min  Last verified: 25 May 2026 Affected versions: Arch Linux (rolling release) 📖 ~4 min read  •  Source: Arch ASA ASA-202101-19 Related CVEs: CVE-2021-1056 CVE-2021-1053 CVE-2021-1052 CVE-2021-1095 CVE-2021-1094 CVE-2021-1093 Upstream summary: Type: multiple issues. Status: Fixed. Affected: 455.45.01-1. Fixed in: 460.32.03-1. Group: AVG-1417. Table of contents Symptom & Impact Environment […]

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Common Problems 117516

Ubuntu 20.04 DNS Resolution Fails Intermittently

🟡 Medium   ⏱ 5–30 min  Last verified: 19 May 2026 📖 ~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 Set Up FreeNAS-style ZFS on FreeBSD 12 — step-by-step FreeBSD 12 tutorial on Progressive Robot

How to Set Up FreeNAS-style ZFS on FreeBSD 12

Introduction This guide explains how to Set Up FreeNAS-style ZFS on FreeBSD 12 on FreeBSD 12. FreeBSD uses the pkg(8) binary package manager, rc.conf(5) for service startup configuration, and pf(4) as its primary packet filter. There is no SELinux or AppArmor — instead, FreeBSD provides the MAC (Mandatory Access Control) framework and Capsicum for fine-grained […]

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FreeBSD 13 — apache+mod_ssl+mod_snmp+mod_accel+mod_deflate+ipv — multiple vulnerabilities (3 CVEs) — patch and remediation guide — diagnosis and fix on FreeBSD 13

FreeBSD 13 — apache+mod_ssl+mod_snmp+mod_accel+mod_deflate+ipv — multiple vulnerabilities (3 CVEs) — patch and remediation guide

🟡 Medium   ⏱ 10–30 min  Last verified: 25 May 2026 Affected versions: FreeBSD 13 📖 ~4 min read  •  Source: FreeBSD VuXML VuXML topic: apache — Prevent chunk-size integer overflow on platforms where sizeof(int) < sizeof(long) Related CVEs: CVE-2005-2088 CVE-2005-3352 CVE-2006-3747 Upstream summary: Apache ChangeLog reports: Integer overflow in the ap_proxy_send_fb function in proxy/proxy_util.c […]

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Java FileWriter Example — step-by-step Programming tutorial on Progressive Robot

Java FileWriter Example

URL: https://www.progressiverobot.com/java-filewriter-example/ Java FileWriter Java FileWriter class is a part of java.io package. FileWriter is a sub class of java.io.OutputStreamWriter class. FileWriter is meant for writing streams of characters. FileWriter is used to write to character files. Its write() methods allow you to write character(s) or strings to a file. FileWriters are usually wrapped by […]

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FreeBSD 13 — py36-pyrad — multiple vulnerabilities (2 CVEs) — patch and remediation guide — diagnosis and fix on FreeBSD 13

FreeBSD 13 — py36-pyrad — multiple vulnerabilities (2 CVEs) — patch and remediation guide

🟢 Low   ⏱ 5–15 min  Last verified: 25 May 2026 Affected versions: FreeBSD 13 📖 ~4 min read  •  Source: FreeBSD VuXML VuXML topic: pyrad — multiple vulnerabilities Related CVEs: CVE-2013-0294 CVE-2013-0342 Upstream summary: Nathaniel McCallum reports: packet.py in pyrad before 2.1 uses weak random numbers to generate RADIUS authenticators and hash passwords, which […]

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How To Validate a Login Form With React and Formik — step-by-step Javascript tutorial on Progressive Robot

How To Validate a Login Form With React and Formik

In order to ensure that the form element of your web application is returning valid data, it is helpful to build automated validation into your code. This is true in React as well; creating form validation early on can often save you from encountering errors down the road. In this tutorial, you will create a React project, add the Formik package, customize the Formik component with an onSubmit callback and a validate function for error messages, then display those error messages to the user.

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