Mitigating Log4Shell in Log4j with Group-IB

A critical deserialization vulnerability in Apache Log4j (Log4Shell, CVE-2021-44228, CVSS 10.0) is widely exploitable and actively being scanned/exploited, potentially affecting millions of Java-based applications; the report summarizes urgency from CISA and Group-IB and provides remediation and mitigation guidance (patching, network restrictions, DNS controls, log inspection), noting that ransomware groups such as Conti may leverage the exploit for lateral movement.