Mitigating Log4Shell and Other Log4j-Related Vulnerabilities

CISA, the Federal Bureau of Investigation (FBI), the National Security Agency (NSA), and the cybersecurity authorities of Australia, Canada, New Zealand, and the United Kingdom have released a joint Cybersecurity Advisory in response to multiple vulnerabilities in Apache’s Log4j software library. Malicious cyber actors are actively scanning networks to potentially exploit CVE-2021-44228 (known as “Log4Shell”), CVE-2021-45046, and CVE-2021-45105 in vulnerable systems. According to public reporting, Log4Shell and CVE-2021-45046 are being actively exploited.

This advisory expands on CISA’s previously published guidance, drafted in collaboration with industry members of CISA’s Joint Cyber Defense Collaborative (JCDC), by detailing recommended steps that vendors and organizations with information technology, operational technology/industrial control systems, and cloud assets should take to respond to these vulnerabilities. 

CISA, FBI, NSA, the Australian Cyber Security Centre (ASCS), the Canadian Centre for Cyber Security (CCCS), the Computer Emergency Response Team New Zealand (CERT NZ), the New Zealand National Cyber Security Centre (NZ NCSC), and the United Kingdom’s National Cyber Security Centre (NCSC-UK) assess that exploitation of these vulnerabilities, especially Log4Shell, is likely to increase and continue over an extended period. CISA and its partners strongly urge all organizations to review AA21-356A: Mitigating Log4Shell and Other Log4j-Related Vulnerabilities for detailed mitigations.