Security Update for .NET Core (August 2021) (macOS)

medium Nessus Plugin ID 152489
New! Plugin Severity Now Using CVSS v3

The calculated severity for Plugins has been updated to use CVSS v3 by default. Plugins that do not have a CVSS v3 score will fall back to CVSS v2 for calculating severity. Severity display preferences can be toggled in the settings dropdown.


The remote macOS host is affected by multiple vulnerabilities.


The Microsoft .NET Core installation on the remote host is version 2.1.x prior to 2.1.29, 3.1.x prior to 3.1.18, or 5.x prior to 5.0.9. It is, therefore affected by multiple vulnerabilities, as follows:

- An information disclosure vulnerability exists when dumps created by the tool to collect crash dumps and dumps on demand are created with global read permissions on Linux and macOS. (CVE-2021-34485)

- A denial of service vulnerability exists as server applications providing WebSocket endpoints can be tricked into endlessly looping while trying to read a single WebSocket frame. (CVE-2021-26423)

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


Update .NET Core, remove vulnerable packages and refer to vendor advisory.

See Also

Plugin Details

Severity: Medium

ID: 152489

File Name: macos_ms21_aug_dotnet_core.nasl

Version: 1.4

Type: local

Agent: macosx

Published: 8/11/2021

Updated: 8/19/2021

Dependencies: macosx_dotnet_core_installed.nbin

Risk Information

CVSS Score Source: CVE-2021-34485


Risk Factor: Low

Score: 3.6


Risk Factor: Low

Base Score: 2.1

Temporal Score: 1.6

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

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


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:H/I:N/A:N

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

Vulnerability Information

CPE: cpe:/a:microsoft:.net_core

Required KB Items: installed_sw/.NET Core MacOS

Exploit Ease: No known exploits are available

Patch Publication Date: 8/10/2021

Vulnerability Publication Date: 8/10/2021

Reference Information

CVE: CVE-2021-26423, CVE-2021-34485

IAVA: 2021-A-0379