An anonymous reader quotes a report from TechCrunch: A severe security vulnerability affecting almost every version of the Linux operating system has caught defenders off-guard and scrambling to patch after security researchers publicly released exploit code that allows attackers to take complete control of vulnerable systems. The U.S. government says the bug, dubbed "CopyFail," is now being exploited in the wild, meaning it's being actively used in malicious hacking campaigns. [...] Given the risk to the federal enterprise network, U.S. cybersecurity agency CISA has ordered all civilian federal agencies to patch any affected systems by May 15.