Security Update for .NET Core (January 2020) - Nessus

High Plugin ID: 132993

This page contains detailed information about the Security Update for .NET Core (January 2020) Nessus plugin including available exploits and PoCs found on GitHub, in Metasploit or Exploit-DB for verifying of this vulnerability.

Table Of Contents

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Plugin Overview
Vulnerability Information

Synopsis
Description
Solution

Public Exploits
Risk Information
Plugin Source
How to Run
References
Version

Plugin Overview

ID: 132993
Name: Security Update for .NET Core (January 2020)
Filename: smb_nt_ms20_jan_dotnet_core.nasl
Vulnerability Published: 2020-01-14
This Plugin Published: 2020-01-16
Last Modification Time: 2020-05-15
Plugin Version: 1.5
Plugin Type: local
Plugin Family: Windows
Dependencies: microsoft_dotnet_core_win.nbin
Required KB Items [?]: installed_sw/.NET Core Windows

Vulnerability Information

Severity: High
Vulnerability Published: 2020-01-14
Patch Published: 2020-01-14
CVE [?]: CVE-2020-0605, CVE-2020-0606
CPE [?]: cpe:/a:microsoft:.net_core

Synopsis

The remote Windows host is affected by multiple .NET Core vulnerabilities.

Description

The Microsoft .NET Core installation on the remote host is version 3.0.x < 3.0.2 or 3.1.x < 3.1.1. It is, therefore, affected by multiple vulnerabilities:

- A remote code execution vulnerability exists in .NET software when the software fails to check the source markup of a file. An attacker who successfully exploited the vulnerability could run arbitrary code in the context of the current user. If the current user is logged on with administrative user rights, an attacker could take control of the affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights. (CVE-2020-0605, CVE-2020-0606)

Solution

Refer to vendor documentation.

Public Exploits

Target Network Port(s): N/A
Target Asset(s): N/A
Exploit Available: True (GitHub)
Exploit Ease: Exploits (PoCs) are available

Here's the list of publicly known exploits and PoCs for verifying the Security Update for .NET Core (January 2020) vulnerability:

GitHub: https://github.com/pwntester/ysoserial.net
[CVE-2020-0605]
GitHub: https://github.com/HeiTang/ZYXEl-CTF-WriteUp
[CVE-2020-0606]

Before running any exploit against any system, make sure you are authorized by the owner of the target system(s) to perform such activity. In any other case, this would be considered as an illegal activity.

WARNING: Beware of using unverified exploits from sources such as GitHub or Exploit-DB. These exploits and PoCs could contain malware. For more information, see how to use exploits safely.

Risk Information

CVSS Score Source [?]: CVE-2020-0606
CVSS V2 Vector: AV:N/AC:M/Au:N/C:C/I:C/A:C/E:U/RL:OF/RC:C

CVSS Base Score:	9.3 (High)
Impact Subscore:	10.0
Exploitability Subscore:	8.6
CVSS Temporal Score:	6.9 (Medium)
CVSS Environmental Score:	NA (None)
Modified Impact Subscore:	NA
Overall CVSS Score:	6.9 (Medium)

CVSS V3 Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

CVSS Base Score:	8.8 (High)
Impact Subscore:	5.9
Exploitability Subscore:	2.8
CVSS Temporal Score:	7.7 (High)
CVSS Environmental Score:	NA (None)
Modified Impact Subscore:	NA
Overall CVSS Score:	7.7 (High)

STIG Severity [?]: I
STIG Risk Rating: High

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Plugin Source

#
# (C) Tenable Network Security, Inc.
#

# The descriptive text and package checks in this plugin were
# extracted from the Microsoft Security Updates API. The text
# itself is copyright (C) Microsoft Corporation.
#

include('compat.inc');

if (description)
{
  script_id(132993);
  script_version("1.5");
  script_set_attribute(attribute:"plugin_modification_date", value:"2020/05/15");

  script_cve_id("CVE-2020-0605", "CVE-2020-0606");
  script_xref(name:"IAVA", value:"2020-A-0031-S");

  script_name(english:"Security Update for .NET Core (January 2020)");
  script_summary(english:"Checks for Windows Install of .NET Core.");

  script_set_attribute(attribute:"synopsis", value:
"The remote Windows host is affected by multiple .NET Core vulnerabilities.");
  script_set_attribute(attribute:"description", value:
"The Microsoft .NET Core installation on the remote host is version 3.0.x < 3.0.2 or 3.1.x < 3.1.1. It is, therefore,
affected by multiple vulnerabilities:

  - A remote code execution vulnerability exists in .NET software when the software fails to check the source markup of
    a file. An attacker who successfully exploited the vulnerability could run arbitrary code in the context of the
    current user. If the current user is logged on with administrative user rights, an attacker could take control of
    the affected system. An attacker could then install programs; view, change, or delete data; or create new accounts
    with full user rights. Users whose accounts are configured to have fewer user rights on the system could be less
    impacted than users who operate with administrative user rights. (CVE-2020-0605, CVE-2020-0606)");
  # https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-0605
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?4e287012");
  # https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-0606
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?fa0a6c3c");
  script_set_attribute(attribute:"see_also", value:"https://github.com/dotnet/announcements/issues/148");
  script_set_attribute(attribute:"see_also", value:"https://github.com/dotnet/announcements/issues/149");
  script_set_attribute(attribute:"solution", value:
"Refer to vendor documentation.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2020-0606");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");

  script_set_attribute(attribute:"vuln_publication_date", value:"2020/01/14");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/01/14");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/01/16");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:microsoft:.net_core");
  script_set_attribute(attribute:"stig_severity", value:"I");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Windows");

  script_copyright(english:"This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("microsoft_dotnet_core_win.nbin");
  script_require_keys("installed_sw/.NET Core Windows");

  exit(0);
}

include('vcf.inc');

app = '.NET Core Windows';
app_info = vcf::get_app_info(app:app, win_local:TRUE);

constraints = [
  { 'min_version' : '3.0.0', 'fixed_version' : '3.0.2' },
  { 'min_version' : '3.1.0', 'fixed_version' : '3.1.1' }
];

vcf::check_version_and_report(app_info:app_info, constraints:constraints, severity:SECURITY_HOLE);

The latest version of this script can be found in these locations depending on your platform:

Linux / Unix:
/opt/nessus/lib/nessus/plugins/smb_nt_ms20_jan_dotnet_core.nasl
Windows:
C:\ProgramData\Tenable\Nessus\nessus\plugins\smb_nt_ms20_jan_dotnet_core.nasl
Mac OS X:
/Library/Nessus/run/lib/nessus/plugins/smb_nt_ms20_jan_dotnet_core.nasl

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How to Run

Here is how to run the Security Update for .NET Core (January 2020) as a standalone plugin via the Nessus web user interface (https://localhost:8834/):

Click to start a New Scan.
Select Advanced Scan.
Navigate to the Plugins tab.
On the top right corner click to Disable All plugins.
On the left side table select Windows plugin family.
On the right side table select Security Update for .NET Core (January 2020) plugin ID 132993.
Specify the target on the Settings tab and click to Save the scan.
Run the scan.

Here are a few examples of how to run the plugin in the command line. Note that the examples below demonstrate the usage on the Linux / Unix platform.

Basic usage:

/opt/nessus/bin/nasl smb_nt_ms20_jan_dotnet_core.nasl -t <IP/HOST>

Run the plugin with audit trail message on the console:

/opt/nessus/bin/nasl -a smb_nt_ms20_jan_dotnet_core.nasl -t <IP/HOST>

Run the plugin with trace script execution written to the console (useful for debugging):

/opt/nessus/bin/nasl -T - smb_nt_ms20_jan_dotnet_core.nasl -t <IP/HOST>

Run the plugin with using a state file for the target and updating it (useful for running multiple plugins on the target):

/opt/nessus/bin/nasl -K /tmp/state smb_nt_ms20_jan_dotnet_core.nasl -t <IP/HOST>

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References

IAVA | Information Assurance Vulnerability Alert:

2020-A-0031-S

See also:

Similar and related Nessus plugins:

132857 - KB4528760: Windows 10 Version 1903 and Windows 10 Version 1909 January 2020 Security Update
132858 - KB4534271: Windows 10 Version 1607 and Windows Server 2016 January 2020 Security Update
132859 - KB4534273: Windows 10 Version 1809 and Windows Server 2019 January 2020 Security Update
132860 - KB4534276: Windows 10 Version 1709 January 2020 Security Update
132861 - KB4534288: Windows Server 2012 January 2020 Security Update
132862 - KB4534293: Windows 10 Version 1803 January 2020 Security Update
132864 - KB4534312: Windows Server 2008 January 2020 Security Update
132865 - KB4534306: Windows 10 January 2020 Security Update
132866 - KB4534314: Windows 7 and Windows Server 2008 R2 January 2020 Security Update
132994 - Security Update for .NET Core SDK (January 2020)
132999 - Security Updates for Microsoft .NET Framework (January 2020)
133042 - Oracle Secure Global Desktop Multiple Vulnerabilities (January 2020 CPU)
132863 - KB4534309: Windows 8.1 and Windows Server 2012 R2 January 2020 Security Update

Version

This page has been produced using Nessus Professional 10.1.2 (#68) LINUX, Plugin set 202205072148.
Plugin file smb_nt_ms20_jan_dotnet_core.nasl version 1.5. For more plugins, visit the Nessus Plugin Library.

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Security Update for .NET Core (January 2020) - Nessus

Plugin Overview

Vulnerability Information

Synopsis

Description

Solution

Public Exploits

Risk Information

Plugin Source

How to Run

References

Version

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