Palo Alto Networks has released urgent fixes for a maximum severity zero-day vulnerability in their PAN-OS firewall software, identified as CVE-2024-3400. This severe flaw allows unauthenticated attackers to execute malicious code with root privileges and risks remote code execution (RCE). The vulnerability, affecting the GlobalProtect feature, has been exploited in targeted attacks by highly capable threat actors, prompting the release of critical hotfixes. The Cybersecurity and Infrastructure Security Agency (CISA) has added this command injection flaw to its Known Exploited Vulnerabilities catalog. Researchers have also released exploit code for this actively exploited bug.