A total of four security issues affect Ubuntu 14.04 LTS (Trusty Tahr) operating systems running the Linux 3.13.0 kernel, as well as official derivatives, including Kubuntu, Xubuntu, Lubuntu, etc. All supported architectures are affected, including 64-bit (amd64), 32-bit (i386), PowerPC (PPC), and PowerPC64 (PPC64). The first and most important security flaw (CVE-2017-7482) fixed in this update was discovered by ?????? in Linux kernel’s RxRPC Kerberos 5 ticket handling code, which incorrectly verified metadata, allowing a remote attacker to either execute arbitrary code or crash the vulnerable system via a denial of service.