Amazon Linux AMI : kernel (ALAS-2016-648)
Medium Nessus Plugin ID 88660
SynopsisThe remote Amazon Linux AMI host is missing a security update.
DescriptionThe Linux kernel before 4.4.1 allows local users to bypass file-descriptor limits and cause a denial of service (memory consumption) by sending each descriptor over a UNIX socket before closing it, related to net/unix/af_unix.c and net/unix/garbage.c.
A race condition in the tty_ioctl function in drivers/tty/tty_io.c in the Linux kernel through 4.4.1 was found that allows local users to obtain sensitive information from kernel memory or cause a denial of service (use-after-free and system crash) by making a TIOCGETD ioctl call during processing of a TIOCSETD ioctl call. (CVE-2016-0723)
A privilege-escalation vulnerability was discovered in the Linux kernel built with User Namespace (CONFIG_USER_NS) support. The flaw occurred when the ptrace() system call was used on a root-owned process to enter a user namespace. A privileged namespace user could exploit this flaw to potentially escalate their privileges on the system, outside the original namespace. (CVE-2015-8709)
net/sctp/sm_sideeffect.c in the Linux kernel before 4.3 does not properly manage the relationship between a lock and a socket, which allows local users to cause a denial of service (deadlock) via a crafted sctp_accept call. (CVE-2015-8767)
SolutionRun 'yum clean all' followed by 'yum update kernel' to update your system. You will need to reboot your system in order for the new kernel to be running.