Amazon Linux AMI : kernel (ALAS-2015-476)
High Nessus Plugin ID 81322
SynopsisThe remote Amazon Linux AMI host is missing a security update.
DescriptionThe Linux kernel through 3.17.4 does not properly restrict dropping of supplemental group memberships in certain namespace scenarios, which allows local users to bypass intended file permissions by leveraging a POSIX ACL containing an entry for the group category that is more restrictive than the entry for the other category, aka a 'negative groups' issue, related to kernel/groups.c, kernel/uid16.c, and kernel/user_namespace.c. (CVE-2014-8989)
A flaw was found in the way the Linux kernel's splice() system call validated its parameters. On certain file systems, a local, unprivileged user could use this flaw to write past the maximum file size, and thus crash the system. (CVE-2014-7822)
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.