Amazon Linux AMI : kernel (ALAS-2020-1366)

high Nessus Plugin ID 136627
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Synopsis

The remote Amazon Linux AMI host is missing a security update.

Description

A NULL pointer dereference flaw was found in the Linux kernel's SELinux subsystem. This flaw occurs while importing the Commercial IP Security Option (CIPSO) protocol's category bitmap into the SELinux extensible bitmap via the' ebitmap_netlbl_import' routine. While processing the CIPSO restricted bitmap tag in the 'cipso_v4_parsetag_rbm' routine, it sets the security attribute to indicate that the category bitmap is present, even if it has not been allocated. This issue leads to a NULL pointer dereference issue while importing the same category bitmap into SELinux. This flaw allows a remote network user to crash the system kernel, resulting in a denial of service. (CVE-2020-10711)

A flaw was found in the Linux kernel loose validation of child/parent process identification handling while filtering signal handlers. A local attacker is able to abuse this flaw to bypass checks to send any signal to a privileged process. (CVE-2020-12826)

A flaw was found in the Linux kernel's implementation of the BFQ IO scheduler. This flaw allows a local user able to groom system memory to cause kernel memory corruption and possible privilege escalation by abusing a race condition in the IO scheduler. (CVE-2020-12657)

Solution

Run 'yum update kernel' to update your system.

See Also

https://alas.aws.amazon.com/ALAS-2020-1366.html

Plugin Details

Severity: High

ID: 136627

File Name: ala_ALAS-2020-1366.nasl

Version: 1.5

Type: local

Agent: unix

Published: 5/15/2020

Updated: 6/22/2020

Dependencies: ssh_get_info.nasl

Risk Information

CVSS Score Source: CVE-2020-12657

VPR

Risk Factor: Medium

Score: 5.9

CVSS v2

Risk Factor: Medium

Base Score: 4.6

Temporal Score: 3.4

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

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

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 6.8

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

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

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:kernel, p-cpe:/a:amazon:linux:kernel-debuginfo, p-cpe:/a:amazon:linux:kernel-debuginfo-common-i686, p-cpe:/a:amazon:linux:kernel-debuginfo-common-x86_64, p-cpe:/a:amazon:linux:kernel-devel, p-cpe:/a:amazon:linux:kernel-headers, p-cpe:/a:amazon:linux:kernel-tools, p-cpe:/a:amazon:linux:kernel-tools-debuginfo, p-cpe:/a:amazon:linux:kernel-tools-devel, p-cpe:/a:amazon:linux:perf, p-cpe:/a:amazon:linux:perf-debuginfo, cpe:/o:amazon:linux

Required KB Items: Host/local_checks_enabled, Host/AmazonLinux/release, Host/AmazonLinux/rpm-list

Exploit Ease: No known exploits are available

Patch Publication Date: 6/17/2020

Vulnerability Publication Date: 5/5/2020

Reference Information

CVE: CVE-2020-10711, CVE-2020-12657, CVE-2020-12826

ALAS: 2020-1366