Ubuntu Security Notice 2910-1 - halfdog discovered that OverlayFS, when mounting on top of a FUSE mount, incorrectly propagated file attributes, including setuid. A local unprivileged attacker could use this to gain privileges. halfdog discovered that OverlayFS in the Linux kernel incorrectly propagated security sensitive extended attributes, such as POSIX ACLs. A local unprivileged attacker could use this to gain privileges. Various other issues were also addressed.
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Ubuntu Security Notice USN-2910-1
February 22, 2016
linux-lts-vivid vulnerabilities
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A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 14.04 LTS
Summary:
Several security issues were fixed in the kernel.
Software Description:
- linux-lts-vivid: Linux hardware enablement kernel from Vivid
Details:
halfdog discovered that OverlayFS, when mounting on top of a FUSE mount,
incorrectly propagated file attributes, including setuid. A local
unprivileged attacker could use this to gain privileges. (CVE-2016-1576)
halfdog discovered that OverlayFS in the Linux kernel incorrectly
propagated security sensitive extended attributes, such as POSIX ACLs. A
local unprivileged attacker could use this to gain privileges.
(CVE-2016-1575)
It was discovered that the Linux kernel keyring subsystem contained a race
between read and revoke operations. A local attacker could use this to
cause a denial of service (system crash). (CVE-2015-7550)
=E9=83=AD=E6=B0=B8=E5=88=9A discovered that the Linux kernel networking implementation did
not validate protocol identifiers for certain protocol families, A local
attacker could use this to cause a denial of service (system crash) or
possibly gain administrative privileges. (CVE-2015-8543)
Dmitry Vyukov discovered that the pptp implementation in the Linux kernel
did not verify an address length when setting up a socket. A local attacker
could use this to craft an application that exposed sensitive information
=66rom kernel memory. (CVE-2015-8569)
David Miller discovered that the Bluetooth implementation in the Linux
kernel did not properly validate the socket address length for Synchronous
Connection-Oriented (SCO) sockets. A local attacker could use this to
expose sensitive information. (CVE-2015-8575)
It was discovered that the Linux kernel's Filesystem in Userspace (FUSE)
implementation did not handle initial zero length segments properly. A
local attacker could use this to cause a denial of service (unkillable
task). (CVE-2015-8785)
Update instructions:
The problem can be corrected by updating your system to the following
package versions:
Ubuntu 14.04 LTS:
linux-image-3.19.0-51-generic 3.19.0-51.57~14.04.1
linux-image-3.19.0-51-generic-lpae 3.19.0-51.57~14.04.1
linux-image-3.19.0-51-lowlatency 3.19.0-51.57~14.04.1
linux-image-3.19.0-51-powerpc-e500mc 3.19.0-51.57~14.04.1
linux-image-3.19.0-51-powerpc-smp 3.19.0-51.57~14.04.1
linux-image-3.19.0-51-powerpc64-emb 3.19.0-51.57~14.04.1
linux-image-3.19.0-51-powerpc64-smp 3.19.0-51.57~14.04.1
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.
Unless you manually uninstalled the standard kernel metapackages
(e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual,
linux-powerpc), a standard system upgrade will automatically perform
this as well.
References:
https://www.ubuntu.com/usn/usn-2910-1
CVE-2015-7550, CVE-2015-8543, CVE-2015-8569, CVE-2015-8575,
CVE-2015-8785, CVE-2016-1575, CVE-2016-1576
Package Information:
https://launchpad.net/ubuntu/+source/linux-lts-vivid/3.19.0-51.57~14.04.1