USN-3169-2: Linux kernel (Xenial HWE) vulnerabilities | Cloud Foundry


# # **Severity** Medium # **Vendor** Ubuntu # **Versions Affected** * Ubuntu 14.04 LTS # **Description** Dmitry Vyukov discovered that the KVM implementation in the Linux kernel did not properly initialize the Code Segment (CS) in certain error cases. A local attacker could use this to expose sensitive information (kernel memory). ([CVE-2016-9756](<http://people.canonical.com/~ubuntu-security/cve/2016/CVE-2016-9756.html>)) Andrey Konovalov discovered that signed integer overflows existed in the setsockopt() system call when handling the SO_SNDBUFFORCE andSO_RCVBUFFORCE options. A local attacker with the CAP_NET_ADMIN capability could use this to cause a denial of service (system crash or memory corruption). ([CVE-2016-9793](<http://people.canonical.com/~ubuntu-security/cve/2016/CVE-2016-9793.html>)) Baozeng Ding discovered a race condition that could lead to a use-after-free in the Advanced Linux Sound Architecture (ALSA) subsystem of the Linux kernel. A local attacker could use this to cause a denial of service(system crash). ([CVE-2016-9794](<http://people.canonical.com/~ubuntu-security/cve/2016/CVE-2016-9794.html>)) # **Affected Products and Versions** _Severity is medium unless otherwise noted._ Cloud Foundry BOSH stemcells are vulnerable, including: * * 3151.x versions prior to 3151.7 * 3233.x versions prior to 3233.10 * 3263.x versions prior to 3263.15 * 3312.x versions prior to 3312.17 # **Mitigation** OSS users are strongly encouraged to follow one of the mitigations below: * The Cloud Foundry team recommends upgrading to the following BOSH stemcells: * Upgrade all lower versions of 3151.x to version 3151.7 * Upgrade all lower versions of 3233.x to version 3233.10 * Upgrade all lower versions of 3263.x to version 3263.15 * Upgrade all lower versions of 3312.x to version 3312.17 # **Credit** Dmitry Vyukov, Andrey Konovalov, Baozeng Ding # **References** * [https://www.ubuntu.com/usn/usn-3169-2/](<https://www.ubuntu.com/usn/usn-3169-2/>) * [http://people.canonical.com/~ubuntu-security/cve/2016/CVE-2016-9756.html](<http://people.canonical.com/~ubuntu-security/cve/2016/CVE-2016-9756.html>) * [http://people.canonical.com/~ubuntu-security/cve/2016/CVE-2016-9793.html](<http://people.canonical.com/~ubuntu-security/cve/2016/CVE-2016-9793.html>) * [http://people.canonical.com/~ubuntu-security/cve/2016/CVE-2016-9794.html](<http://people.canonical.com/~ubuntu-security/cve/2016/CVE-2016-9794.html>) # **History** 2017-01-11: Initial vulnerability report published