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Ubuntu 11.04 USN-1285-1 Critical: Kernel Access Flaws and DOS Threats

Several security issues were fixed in the kernel.. =========================================================================Ubuntu Security Notice USN-1285-1 November 29, 2011 linux vulnerabilities ========================================================================= A security issue affects these releases of Ubuntu and its derivatives: - Ubuntu 11.04 Summary: Several security issues were fixed in the kernel. Software Description: - linux: Linux kernel Details: Andrea Righi discovered a race condition in the KSM memory merging support. If KSM was being used, a local attacker could exploit this to crash the system, leading to a denial of service. (CVE-2011-2183) Vasily Averin discovered that the NFS Lock Manager (NLM) incorrectly handled unlock requests. A local attacker could exploit this to cause a denial of service. (CVE-2011-2491) Vasiliy Kulikov discovered that taskstats did not enforce access restrictions. A local attacker could exploit this to read certain information, leading to a loss of privacy. (CVE-2011-2494) Vasiliy Kulikov discovered that /proc/PID/io did not enforce access restrictions. A local attacker could exploit this to read certain information, leading to a loss of privacy. (CVE-2011-2495) It was discovered that the wireless stack incorrectly verified SSID lengths. A local attacker could exploit this to cause a denial of service or gain root privileges. (CVE-2011-2517) Christian Ohm discovered that the perf command looks for configuration files in the current directory. If a privileged user were tricked into running perf in a directory containing a malicious configuration file, an attacker could run arbitrary commands and possibly gain privileges. (CVE-2011-2905) Vasiliy Kulikov discovered that the Comedi driver did not correctly clear memory. A local attacker could exploit this to read kernel stack memory, leading to a loss of privacy. (CVE-2011-2909) Update instructions: The problem can be corrected by updating yoursystem to the following package versions: Ubuntu 11.04: linux-image-2.6.38-13-generic 2.6.38-13.52 linux-image-2.6.38-13-generic-pae 2.6.38-13.52 linux-image-2.6.38-13-omap 2.6.38-13.52 linux-image-2.6.38-13-powerpc 2.6.38-13.52 linux-image-2.6.38-13-powerpc-smp 2.6.38-13.52 linux-image-2.6.38-13-powerpc64-smp 2.6.38-13.52 linux-image-2.6.38-13-server 2.6.38-13.52 linux-image-2.6.38-13-versatile 2.6.38-13.52 linux-image-2.6.38-13-virtual 2.6.38-13.52 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: https://ubuntu.com/security/notices/USN-1285-1 CVE-2011-2183, CVE-2011-2491, CVE-2011-2494, CVE-2011-2495, CVE-2011-2517, CVE-2011-2905, CVE-2011-2909 Package Information: https://launchpad.net/ubuntu/+source/linux/2.6.38-13.52 . Major kernel vulnerabilities addressed in Ubuntu 11.04 highlighting denial of service risks and accessibility concerns. Users should apply updates urgently.. Ubuntu Security Notice,Linux Kernel Security,DOS Exploits,Kernel Update. . Severity: Critical. LinuxSecurity.com Team

Nov 29, 2011 •Critical Ubuntu