Several security issues were fixed in the kernel.
It was discovered that the Linux kernel did not check if a new IPv6 MTU set by a user space application was valid. A remote attacker could forge a route advertisement with an invalid MTU that a user space daemon like NetworkManager would honor and apply to the kernel, causing a denial of service. (CVE-2015-0272)
5 November 2015
A security issue affects these releases of Ubuntu and its derivatives:
Several security issues were fixed in the kernel.
It was discovered that the Linux kernel did not check if a new IPv6 MTU set by a user space application was valid. A remote attacker could forge a route advertisement with an invalid MTU that a user space daemon like NetworkManager would honor and apply to the kernel, causing a denial of service. (CVE-2015-0272)
It was discovered that in certain situations, a directory could be renamed outside of a bind mounted location. An attacker could use this to escape bind mount containment and gain access to sensitive information. (CVE-2015-2925)
Moein Ghasemzadeh discovered that the USB WhiteHEAT serial driver contained hardcoded attributes about the USB devices. An attacker could construct a fake WhiteHEAT USB device that, when inserted, causes a denial of service (system crash). (CVE-2015-5257)
It was discovered that the SCTP protocol implementation in the Linux kernel performed an incorrect sequence of protocol-initialization steps. A local attacker could use this to cause a denial of service (system crash). (CVE-2015-5283)
The problem can be corrected by updating your system to the following package versions:
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
After a standard system update you need to reboot your computer to make all the necessary changes.
ATTENTION: Due to an unavoidable ABI change the kernel updates have been given a new version number, which requires you to recompile and reinstall all third party kernel modules you might have installed. If you use linux-restricted-modules, you have to update that package as well to get modules which work with the new kernel version. Unless you manually uninstalled the standard kernel metapackages (e.g. linux-generic, linux-server, linux-powerpc), a standard system upgrade will automatically perform this as well.