Ubuntu 16.04 LTS : linux-hwe, linux-gcp vulnerabilities (USN-3836-2)

high Nessus Plugin ID 119340
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Synopsis

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

Description

USN-3836-1 fixed vulnerabilities in the Linux kernel for Ubuntu 18.04 LTS. This update provides the corresponding updates for the Linux Hardware Enablement (HWE) kernel from Ubuntu 18.04 LTS for Ubuntu 16.04 LTS.

Jann Horn discovered that the Linux kernel mishandles mapping UID or GID ranges inside nested user namespaces in some situations. A local attacker could use this to bypass access controls on resources outside the namespace. (CVE-2018-18955)

Philipp Wendler discovered that the overlayfs implementation in the Linux kernel did not properly verify the directory contents permissions from within a unprivileged user namespace. A local attacker could use this to expose sensitive information (protected file names). (CVE-2018-6559).

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 packages.

See Also

https://usn.ubuntu.com/3836-2/

Plugin Details

Severity: High

ID: 119340

File Name: ubuntu_USN-3836-2.nasl

Version: 1.6

Type: local

Agent: unix

Published: 12/4/2018

Updated: 9/18/2019

Dependencies: ssh_get_info.nasl, linux_alt_patch_detect.nasl

Risk Information

VPR

Risk Factor: High

Score: 7.4

CVSS v2

Risk Factor: Medium

Base Score: 4.4

Temporal Score: 3.6

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

Temporal Vector: E:F/RL:OF/RC:C

CVSS v3

Risk Factor: High

Base Score: 7

Temporal Score: 6.5

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

Temporal Vector: E:F/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15-gcp, p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15-generic, p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15-generic-lpae, p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15-lowlatency, p-cpe:/a:canonical:ubuntu_linux:linux-image-gcp, p-cpe:/a:canonical:ubuntu_linux:linux-image-generic-hwe-16.04, p-cpe:/a:canonical:ubuntu_linux:linux-image-generic-lpae-hwe-16.04, p-cpe:/a:canonical:ubuntu_linux:linux-image-gke, p-cpe:/a:canonical:ubuntu_linux:linux-image-lowlatency-hwe-16.04, p-cpe:/a:canonical:ubuntu_linux:linux-image-oem, cpe:/o:canonical:ubuntu_linux:16.04

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

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 12/4/2018

Vulnerability Publication Date: 10/26/2018

Exploitable With

Metasploit (Linux Nested User Namespace idmap Limit Local Privilege Escalation)

Reference Information

CVE: CVE-2018-18955, CVE-2018-6559

USN: 3836-2