Ubuntu 14.04 LTS : Linux kernel (Utopic HWE) vulnerabilities (USN-2849-1)

high Nessus Plugin ID 87532

Synopsis

The remote Ubuntu host is missing one or more security updates.

Description

The remote Ubuntu 14.04 LTS host has a package installed that is affected by multiple vulnerabilities as referenced in the USN-2849-1 advisory.

- Xen, when used on a system providing PV backends, allows local guest OS administrators to cause a denial of service (host OS crash) or gain privileges by writing to memory shared between the frontend and backend, aka a double fetch vulnerability. (CVE-2015-8550)

- The PCI backend driver in Xen, when running on an x86 system and using Linux 3.1.x through 4.3.x as the driver domain, allows local guest administrators to hit BUG conditions and cause a denial of service (NULL pointer dereference and host OS crash) by leveraging a system with access to a passed-through MSI or MSI-X capable physical PCI device and a crafted sequence of XEN_PCI_OP_* operations, aka Linux pciback missing sanity checks. (CVE-2015-8551)

- The PCI backend driver in Xen, when running on an x86 system and using Linux 3.1.x through 4.3.x as the driver domain, allows local guest administrators to generate a continuous stream of WARN messages and cause a denial of service (disk consumption) by leveraging a system with access to a passed-through MSI or MSI-X capable physical PCI device and XEN_PCI_OP_enable_msi operations, aka Linux pciback missing sanity checks. (CVE-2015-8552)

- kernel/ptrace.c in the Linux kernel through 4.4.1 mishandles uid and gid mappings, which allows local users to gain privileges by establishing a user namespace, waiting for a root process to enter that namespace with an unsafe uid or gid, and then using the ptrace system call. NOTE: the vendor states there is no kernel bug here. (CVE-2015-8709)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Update the affected kernel package.

See Also

https://ubuntu.com/security/notices/USN-2849-1

Plugin Details

Severity: High

ID: 87532

File Name: ubuntu_USN-2849-1.nasl

Version: 2.17

Type: local

Agent: unix

Published: 12/21/2015

Updated: 1/9/2024

Supported Sensors: Agentless Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Frictionless Assessment Azure, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: Medium

Base Score: 6.9

Temporal Score: 5.1

Vector: CVSS2#AV:L/AC:M/Au:N/C:C/I:C/A:C

CVSS Score Source: CVE-2015-8709

CVSS v3

Risk Factor: High

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

CVSS Score Source: CVE-2015-8550

Vulnerability Information

CPE: p-cpe:/a:canonical:ubuntu_linux:linux-image-3.16.0-57-generic, p-cpe:/a:canonical:ubuntu_linux:linux-image-3.16.0-57-generic-lpae, p-cpe:/a:canonical:ubuntu_linux:linux-image-3.16.0-57-lowlatency, p-cpe:/a:canonical:ubuntu_linux:linux-image-3.16.0-57-powerpc-e500mc, p-cpe:/a:canonical:ubuntu_linux:linux-image-3.16.0-57-powerpc-smp, p-cpe:/a:canonical:ubuntu_linux:linux-image-3.16.0-57-powerpc64-emb, p-cpe:/a:canonical:ubuntu_linux:linux-image-3.16.0-57-powerpc64-smp, cpe:/o:canonical:ubuntu_linux:14.04:-:lts

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

Exploit Ease: No known exploits are available

Patch Publication Date: 12/19/2015

Vulnerability Publication Date: 4/13/2016

Reference Information

CVE: CVE-2015-8550, CVE-2015-8551, CVE-2015-8552, CVE-2015-8709

USN: 2849-1