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EulerOS 2.0 SP3 : unbound (EulerOS-SA-2021-1857)

medium Nessus Plugin ID 149150

Synopsis

The remote EulerOS host is missing a security update.

Description

According to the version of the unbound packages installed, the EulerOS installation on the remote host is affected by the following vulnerability :

 - NLnet Labs Unbound, up to and including version 1.12.0, and NLnet Labs NSD, up to and including version 4.3.3, contain a local vulnerability that would allow for a local symlink attack. When writing the PID file, Unbound and NSD create the file if it is not there, or open an existing file for writing. In case the file was already present, they would follow symlinks if the file happened to be a symlink instead of a regular file. An additional chown of the file would then take place after it was written, making the user Unbound/NSD is supposed to run as the new owner of the file. If an attacker has local access to the user Unbound/NSD runs as, she could create a symlink in place of the PID file pointing to a file that she would like to erase. If then Unbound/NSD is killed and the PID file is not cleared, upon restarting with root privileges, Unbound/NSD will rewrite any file pointed at by the symlink. This is a local vulnerability that could create a Denial of Service of the system Unbound/NSD is running on. It requires an attacker having access to the limited permission user Unbound/NSD runs as and point through the symlink to a critical file on the system.(CVE-2020-28935)

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

Solution

Update the affected unbound package.

See Also

http://www.nessus.org/u?a46f9a7e

Plugin Details

Severity: Medium

ID: 149150

File Name: EulerOS_SA-2021-1857.nasl

Version: 1.3

Type: local

Published: 4/30/2021

Updated: 1/2/2024

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3.6

CVSS v2

Risk Factor: Low

Base Score: 2.1

Temporal Score: 1.6

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

CVSS Score Source: CVE-2020-28935

CVSS v3

Risk Factor: Medium

Base Score: 5.5

Temporal Score: 4.8

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

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

Vulnerability Information

CPE: p-cpe:/a:huawei:euleros:unbound, p-cpe:/a:huawei:euleros:unbound-libs, cpe:/o:huawei:euleros:2.0

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

Excluded KB Items: Host/EulerOS/uvp_version

Exploit Ease: No known exploits are available

Patch Publication Date: 4/30/2021

Reference Information

CVE: CVE-2020-28935