USN-1796-1: Linux kernel vulnerabilities
8 April 2013
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 12.10
Several security issues were fixed in the kernel.
- linux - Linux kernel
Andrew Jones discovered a flaw with the xen_iret function in Linux kernel’s Xen virtualizeation. In the 32-bit Xen paravirt platform an unprivileged guest OS user could exploit this flaw to cause a denial of service (crash the system) or gain guest OS privilege. (CVE-2013-0228)
Emese Revfy discovered that in the Linux kernel signal handlers could leak address information across an exec, making it possible to by pass ASLR (Address Space Layout Randomization). A local user could use this flaw to by pass ASLR to reliably deliver an exploit payload that would otherwise be stopped (by ASLR). (CVE-2013-0914)
A memory use after free error was discover in the Linux kernel’s tmpfs filesystem. A local user could exploit this flaw to gain privileges or cause a denial of service (system crash). (CVE-2013-1767)
Mateusz Guzik discovered a race in the Linux kernel’s keyring. A local user could exploit this flaw to cause a denial of service (system crash). (CVE-2013-1792)
Mathias Krause discovered a memory leak in the Linux kernel’s crypto report API. A local user with CAP_NET_ADMIN could exploit this leak to examine some of the kernel’s stack memory. (CVE-2013-2546)
Mathias Krause discovered a memory leak in the Linux kernel’s crypto report API. A local user with CAP_NET_ADMIN could exploit this leak to examine some of the kernel’s heap memory. (CVE-2013-2547)
Mathias Krause discovered information leaks in the Linux kernel’s crypto algorithm report API. A local user could exploit these flaws to leak kernel stack and heap memory contents. (CVE-2013-2548)
The problem can be corrected by updating your system to the following package versions:
- Ubuntu 12.10
- linux-image-3.5.0-27-generic - 3.5.0-27.46
- linux-image-3.5.0-27-highbank - 3.5.0-27.46
- linux-image-3.5.0-27-omap - 3.5.0-27.46
- linux-image-3.5.0-27-powerpc-smp - 3.5.0-27.46
- linux-image-3.5.0-27-powerpc64-smp - 3.5.0-27.46
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.