Executive Summary

Summary
Title Linux kernel vulnerabilities
Informations
NameUSN-3835-1First vendor Publication2018-12-03
VendorUbuntuLast vendor Modification2018-12-03
Severity (Vendor) N/ARevisionN/A

Security-Database Scoring CVSS v2

Cvss vector : (AV:L/AC:L/Au:N/C:C/I:C/A:C)
Cvss Base Score7.2Attack RangeLocal
Cvss Impact Score10Attack ComplexityLow
Cvss Expoit Score3.9AuthenticationNone Required
Calculate full CVSS 2.0 Vectors scores

Detail

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 18.10

Summary:

Several security issues were fixed in the Linux kernel.

Software Description: - linux: Linux kernel - linux-gcp: Linux kernel for Google Cloud Platform (GCP) systems - linux-kvm: Linux kernel for cloud environments - linux-raspi2: Linux kernel for Raspberry Pi 2

Details:

Jann Horn discovered that the procfs file system implementation in the Linux kernel did not properly restrict the ability to inspect the kernel stack of an arbitrary task. A local attacker could use this to expose sensitive information. (CVE-2018-17972)

Jann Horn discovered that the mremap() system call in the Linux kernel did not properly flush the TLB when completing, potentially leaving access to a physical page after it has been released to the page allocator. A local attacker could use this to cause a denial of service (system crash), expose sensitive information, or possibly execute arbitrary code. (CVE-2018-18281)

It was discovered that the BPF verifier in the Linux kernel did not correctly compute numeric bounds in some situations. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-18445)

Daniel Dadap discovered that the module loading implementation in the Linux kernel did not properly enforce signed module loading when booted with UEFI Secure Boot in some situations. A local privileged attacker could use this to execute untrusted code in the kernel. (CVE-2018-18653)

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)

Update instructions:

The problem can be corrected by updating your system to the following package versions:

Ubuntu 18.10:
linux-image-4.18.0-1004-gcp 4.18.0-1004.5
linux-image-4.18.0-1005-kvm 4.18.0-1005.5
linux-image-4.18.0-1007-raspi2 4.18.0-1007.9
linux-image-4.18.0-12-generic 4.18.0-12.13
linux-image-4.18.0-12-generic-lpae 4.18.0-12.13
linux-image-4.18.0-12-lowlatency 4.18.0-12.13
linux-image-4.18.0-12-snapdragon 4.18.0-12.13
linux-image-gcp 4.18.0.1004.4
linux-image-generic 4.18.0.12.13
linux-image-generic-lpae 4.18.0.12.13
linux-image-gke 4.18.0.1004.4
linux-image-kvm 4.18.0.1005.5
linux-image-lowlatency 4.18.0.12.13
linux-image-raspi2 4.18.0.1007.4
linux-image-snapdragon 4.18.0.12.13

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://usn.ubuntu.com/usn/usn-3835-1
CVE-2018-17972, CVE-2018-18281, CVE-2018-18445, CVE-2018-18653,
CVE-2018-18955, CVE-2018-6559

Package Information:
https://launchpad.net/ubuntu/+source/linux/4.18.0-12.13
https://launchpad.net/ubuntu/+source/linux-gcp/4.18.0-1004.5
https://launchpad.net/ubuntu/+source/linux-kvm/4.18.0-1005.5
https://launchpad.net/ubuntu/+source/linux-raspi2/4.18.0-1007.9

Original Source

Url : http://www.ubuntu.com/usn/USN-3835-1

CWE : Common Weakness Enumeration

%idName
33 %CWE-284Access Control (Authorization) Issues
33 %CWE-200Information Exposure
33 %CWE-125Out-of-bounds Read

CPE : Common Platform Enumeration

TypeDescriptionCount
Os4
Os2968

Nessus® Vulnerability Scanner

DateDescription
2018-11-09Name : The remote Amazon Linux 2 host is missing a security update.
File : al2_ALAS-2018-1100.nasl - Type : ACT_GATHER_INFO
2018-11-08Name : The remote Amazon Linux AMI host is missing a security update.
File : ala_ALAS-2018-1100.nasl - Type : ACT_GATHER_INFO
2018-10-17Name : The remote Fedora host is missing one or more security updates.
File : fedora_2018-2ee3411cb8.nasl - Type : ACT_GATHER_INFO

Alert History

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0
1
DateInformations
2018-12-06 17:21:07
  • Multiple Updates
2018-12-04 00:18:44
  • First insertion