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  • Another Log4j Bug – DoS Java
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  • Fixing Log4j Vulnerability Java
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Category: Java

Another Log4j Bug – DoS

Posted on December 20, 2021December 22, 2021 By Santhosh Ponnam

Denial of Service (DoS) which is another Log4J Bug reported over the last couple of days after the fix for JNDI is provided. Apache Issues Fix and the new Log4j vulnerability is similar to Log4Shell but this DoS flaw has to do with Context Map lookups. Apache released another patch version 2.17.0 to address the…

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Java

Log4j Vulnerability / Version Upgrade to 2.16.0 by Apache Team

Posted on December 14, 2021December 22, 2021 By Santhosh Ponnam

A new version of Log4j with 2.16.0 has been released to address the JNDI issue to further prevent the CVE-2021-44228 permanently. While release 2.15.0 removed the ability to resolve Lookups and log messages and addressed issues with how JNDI is accessed, the Log4j team feels that having JNDI enabled by default introduces an undue risk…

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Java

Fixing Log4j Vulnerability

Posted on December 11, 2021December 13, 2021 By Santhosh Ponnam

The easiest way to remediate this is to update to log4j version 2.15.0 or later, as this behavior is now disabled by default. In previous releases (>2.10) this behavior can be mitigated by setting the system property log4j2.formatMsgNoLookups to true by adding the following Java parameter: -Dlog4j2.formatMsgNoLookups=true Alternatively, you can mitigate this vulnerability by removing…

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Java, Spring Boot

Log4J (RCE) Vulnerability

Posted on December 11, 2021December 13, 2021 By Santhosh Ponnam

What is the Log4J Vulnerability (CVE-2021-44228 vulnerability) which is creating a panic over java based applications? Lets quickly start with what it is and the remediation’s to fix it on various versions. CVE-2021-44228 is a vulnerability classified under the highest severity mark, i.e. 10 out of 10. It allows an attacker to execute arbitrary code…

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Java

Why to have a private constructor?

Posted on August 13, 2018September 1, 2021 By Santhosh Ponnam

In Java, it is possible to have a private constructor. When and why should we use private constructor is explained in detail below. Defining a constructor with the private modifier says that only the native class (as in the class in which the private constructor is defined) is allowed to create an instance of the…

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Java

hashCode and equals methods in java

Posted on November 2, 2016August 12, 2021 By Santhosh Ponnam

Usage of hashCode() and equals()hashCode() method returns integer for a given object. This integer is used for determining the bucket location, when this object needs to be stored in some HashTable like data structure. By default, Object’s hashCode() method returns an integer representation of memory address where object is stored. equals() method is used to…

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Java

Unique Random ‘N’ digit Number generator

Posted on August 12, 2016August 13, 2021 By Santhosh Ponnam
package com.santhosh.random;

import java.util.Random;

import org.apache.commons.lang3.StringUtils;

public class SequenceGenerator {
    private final Random random;

    public SequenceGenerator() {
        random = new Random();
    }

    /**
     * Returns a pseudo-random integer between 0 and n-1.
     *
     * @see Random#nextInt(int)
     */
    public int nextInt(int n) {
        return random.nextInt(n);
    }

    public static void main(String[] args) {
        SequenceGenerator g = new SequenceGenerator();
        String result = StringUtils.leftPad(String.valueOf(g.nextInt(99999)),
                5, '0');
        System.out.println(result);
    }
}
Java

Setting Environment Variables in Windows

Posted on August 2, 2016August 12, 2021 By Santhosh Ponnam

Why do I need to set JAVA_HOME? Many Java based programs like Tomcat require JAVA_HOME to be set as environment variable to work correctly. Please note JAVA_HOME should point to a JDK directory not a JRE one. The point of setting the environment variable is to let programs know in which directory executables like javac can be…

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Java

Recent Posts

  • Another Log4j Bug – DoS
  • Log4j Vulnerability / Version Upgrade to 2.16.0 by Apache Team
  • Fixing Log4j Vulnerability
  • Log4J (RCE) Vulnerability
  • JPA vs Hibernate – Specification Vs Implementation

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Recent Posts

  • Another Log4j Bug – DoS
  • Log4j Vulnerability / Version Upgrade to 2.16.0 by Apache Team
  • Fixing Log4j Vulnerability
  • Log4J (RCE) Vulnerability
  • JPA vs Hibernate – Specification Vs Implementation

Categories

  • Installations and Configurations
  • Java
  • ORM
  • Spring Boot
  • Spring Boot HikariCP Connection Pooling

Archives

  • December 2021
  • August 2021
  • November 2020
  • March 2020
  • August 2018
  • November 2016
  • August 2016




Recent Posts

  • Another Log4j Bug – DoS
  • Log4j Vulnerability / Version Upgrade to 2.16.0 by Apache Team
  • Fixing Log4j Vulnerability
  • Log4J (RCE) Vulnerability
  • JPA vs Hibernate – Specification Vs Implementation

Categories

  • Installations and Configurations
  • Java
  • ORM
  • Spring Boot
  • Spring Boot HikariCP Connection Pooling
  • hashCode and equals methods in java Java
  • Another Log4j Bug – DoS Java
  • Fixing Log4j Vulnerability Java
  • Why to have a private constructor? Java
  • Windows Commands – kill port number Installations and Configurations
  • Log4J (RCE) Vulnerability Java
  • Log4j Vulnerability / Version Upgrade to 2.16.0 by Apache Team Java
  • HikariCP Configurations – Database Connection Pooling Installations and Configurations

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