Ubuntu 15.10 : linux vulnerabilities (USN-2851-1)

Medium Nessus Plugin ID 87534

Synopsis

The remote Ubuntu host is missing one or more security-related patches.

Description

Felix Wilhelm discovered a race condition in the Xen paravirtualized drivers which can cause double fetch vulnerabilities. An attacker in the paravirtualized guest could exploit this flaw to cause a denial of service (crash the host) or potentially execute arbitrary code on the host. (CVE-2015-8550)

Konrad Rzeszutek Wilk discovered the Xen PCI backend driver does not perform sanity checks on the device's state. An attacker could exploit this flaw to cause a denial of service (NULL dereference) on the host.
(CVE-2015-8551)

Konrad Rzeszutek Wilk discovered the Xen PCI backend driver does not perform sanity checks on the device's state. An attacker could exploit this flaw to cause a denial of service by flooding the logging system with WARN() messages causing the initial domain to exhaust disk space.
(CVE-2015-8552)

Jann Horn discovered a ptrace issue with user namespaces in the Linux kernel. The namespace owner could potentially exploit this flaw by ptracing a root owned process entering the user namespace to elevate its privileges and potentially gain access outside of the namespace.
(http://bugs.launchpad.net/bugs/1527374)

Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

Solution

Update the affected linux-image-4.2-generic, linux-image-4.2-generic-lpae and / or linux-image-4.2-lowlatency packages.

See Also

https://usn.ubuntu.com/2851-1/

Plugin Details

Severity: Medium

ID: 87534

File Name: ubuntu_USN-2851-1.nasl

Version: 2.12

Type: local

Agent: unix

Published: 2015/12/21

Updated: 2019/03/21

Dependencies: 12634, 122878

Risk Information

Risk Factor: Medium

CVSS v2.0

Base Score: 5.7

Temporal Score: 4.2

Vector: CVSS2#AV:L/AC:L/Au:S/C:P/I:P/A:C

Temporal Vector: CVSS2#E:U/RL:OF/RC:C

CVSS v3.0

Base Score: 8.2

Temporal Score: 7.1

Vector: CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:canonical:ubuntu_linux:linux-image-4.2-generic, p-cpe:/a:canonical:ubuntu_linux:linux-image-4.2-generic-lpae, p-cpe:/a:canonical:ubuntu_linux:linux-image-4.2-lowlatency, cpe:/o:canonical:ubuntu_linux:15.10

Required KB Items: Host/cpu, Host/Ubuntu, Host/Ubuntu/release, Host/Debian/dpkg-l

Exploit Available: false

Exploit Ease: No known exploits are available

Patch Publication Date: 2015/12/19

Vulnerability Publication Date: 2016/04/13

Reference Information

CVE: CVE-2015-8550, CVE-2015-8551, CVE-2015-8552

USN: 2851-1