USN-2513-1: Linux kernel vulnerabilities
26 February 2015
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 12.04 LTS
Several security issues were fixed in the kernel.
- linux - Linux kernel
A flaw was discovered in the Kernel Virtual Machine’s (KVM) emulation of the SYSTENTER instruction when the guest OS does not initialize the SYSENTER MSRs. A guest OS user could exploit this flaw to cause a denial of service of the guest OS (crash) or potentially gain privileges on the guest OS. (CVE-2015-0239)
A flaw was discovered in the automatic loading of modules in the crypto subsystem of the Linux kernel. A local user could exploit this flaw to load installed kernel modules, increasing the attack surface and potentially using this to gain administrative privileges. (CVE-2013-7421)
Andy Lutomirski discovered a flaw in how the Linux kernel handles pivot_root when used with a chroot directory. A local user could exploit this flaw to cause a denial of service (mount-tree loop). (CVE-2014-7970)
A restriction bypass was discovered in iptables when conntrack rules are specified and the conntrack protocol handler module is not loaded into the Linux kernel. This flaw can cause the firewall rules on the system to be bypassed when conntrack rules are used. (CVE-2014-8160)
A race condition was discovered in the Linux kernel’s key ring. A local user could cause a denial of service (memory corruption or panic) or possibly have unspecified impact via the keyctl commands. (CVE-2014-9529)
A memory leak was discovered in the ISO 9660 CDROM file system when parsing rock ridge ER records. A local user could exploit this flaw to obtain sensitive information from kernel memory via a crafted iso9660 image. (CVE-2014-9584)
A flaw was discovered in the Address Space Layout Randomization (ASLR) of the Virtual Dynamically linked Shared Objects (vDSO) location. This flaw makes it easier for a local user to bypass the ASLR protection mechanism. (CVE-2014-9585)
A flaw was discovered in the crypto subsystem when screening module names for automatic module loading if the name contained a valid crypto module name, eg. vfat(aes). A local user could exploit this flaw to load installed kernel modules, increasing the attack surface and potentially using this to gain administrative privileges. (CVE-2014-9644)
The problem can be corrected by updating your system to the following package versions:
- Ubuntu 12.04 LTS
- linux-image-3.2.0-77-generic - 3.2.0-77.112
- linux-image-3.2.0-77-generic-pae - 3.2.0-77.112
- linux-image-3.2.0-77-highbank - 3.2.0-77.112
- linux-image-3.2.0-77-omap - 3.2.0-77.112
- linux-image-3.2.0-77-powerpc-smp - 3.2.0-77.112
- linux-image-3.2.0-77-powerpc64-smp - 3.2.0-77.112
- linux-image-3.2.0-77-virtual - 3.2.0-77.112
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.