============================================================================ Ubuntu Security Notice USN-1795-1 April 08, 2013 linux-lts-quantal vulnerabilities ============================================================================ A security issue affects these releases of Ubuntu and its derivatives: - Ubuntu 12.04 LTS Summary: Several security issues were fixed in the kernel. Software Description: - linux-lts-quantal: Linux hardware enablement kernel from Quantal Details: 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) Update instructions: The problem can be corrected by updating your system to the following package versions: Ubuntu 12.04 LTS: linux-image-3.5.0-27-generic 3.5.0-27.46~precise1 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. References: http://www.ubuntu.com/usn/usn-1795-1 CVE-2013-0228, CVE-2013-0914, CVE-2013-1767, CVE-2013-1792, CVE-2013-2546, CVE-2013-2547, CVE-2013-2548 Package Information: https://launchpad.net/ubuntu/+source/linux-lts-quantal/3.5.0-27.46~precise1