Ubuntu 18.04 LTS : linux, linux-gcp, linux-kvm, linux-raspi2 vulnerabilities (USN-3836-1)
Medium Nessus Plugin ID 119339
SynopsisThe remote Ubuntu host is missing one or more security-related patches.
DescriptionJann Horn discovered that the Linux kernel mishandles mapping UID or GID ranges inside nested user namespaces in some situations. A local attacker could use this to bypass access controls on resources outside the namespace. (CVE-2018-18955)
Philipp Wendler discovered that the overlayfs implementation in the Linux kernel did not properly verify the directory contents permissions from within a unprivileged user namespace. A local attacker could use this to expose sensitive information (protected file names). (CVE-2018-6559).
Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
SolutionUpdate the affected packages.