CVE-2021-45046 PoC — Apache Log4j2 Thread Context Message Pattern and Context Lookup Pattern vulnerable to a denial of service attack

Source

https://github.com/lukepasek/log4jjndilookupremove

Associated Vulnerability

Title:Apache Log4j2 Thread Context Message Pattern and Context Lookup Pattern vulnerable to a denial of service attack (CVE-2021-45046)
Description:It was found that the fix to address CVE-2021-44228 in Apache Log4j 2.15.0 was incomplete in certain non-default configurations. This could allows attackers with control over Thread Context Map (MDC) input data when the logging configuration uses a non-default Pattern Layout with either a Context Lookup (for example, $${ctx:loginId}) or a Thread Context Map pattern (%X, %mdc, or %MDC) to craft malicious input data using a JNDI Lookup pattern resulting in an information leak and remote code execution in some environments and local code execution in all environments. Log4j 2.16.0 (Java 8) and 2.12.2 (Java 7) fix this issue by removing support for message lookup patterns and disabling JNDI functionality by default.

Description

A simple script to remove Log4J JndiLookup.class from jars in a given directory, to temporarily protect from CVE-2021-45046 and CVE-2021-44228.

Readme

# log4jjndilookupremove
 A simple script to remove Log4J JndiLookup.class from jars in given directory.
 This script can be used to temporarily resolve the CVE-2021-45046 and CVE-2021-44228, until the application can be repackaged with a proper Log4J version.
 
 ## Usage
 On Linux or other \*nix system just run this script in the directory you want to scan, or add the target directory as first parameter:
 ```
 $. scanjars.sh
 ```
 or
 ```
 $. scanjars.sh <target_dir>
 ```
## Dependencies
* bash
* zip
* unzip

File Snapshot


 [4.0K]  /data/pocs/1f2d4e016248b082d21481f725c406ca39645304
├── [ 534]  README.md
└── [9.8K]  scanjars.sh

0 directories, 2 files

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