CVE-2021-23885: McAfee Security Bulletin - Web Gateway update fixes a Privilege escalation vulnerability (CVE-2021-23885)

First Published: February 16, 2021

Product:

Impacted Versions:

CVE ID:

Impact of Vulnerabilities:

Severity Ratings:

CVSS v3.1
Base/Temporal Scores:

McAfee Web Gateway (MWG)

Prior to:
10.0.4
9.2.8
8.2.17

CVE-2021-23885

CWE-269: Improper Privilege Management

Critical

9.0 / 8.3

Recommendations:

Install or update to MWG 8.2.17, 9.2.8, or 10.0.4

Security Bulletin Replacement:

None

Location of updated software:

http://www.mcafee.com/us/downloads/downloads.aspx

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Article contents:

• Vulnerability Description
• Remediation
• Frequently Asked Questions (FAQs)
• Resources
• Disclaimer

Vulnerability Description
This exploit requires the attacker to gain authenticated access to the MWG User Interface. McAfee recommends that access to the User Interface is restricted to trusted networks and that the number of people authorized to log on is limited. This issue results in commands being executed as root on the MWG appliance.

McAfee is not aware of this issue being exploited in the field.

CVE-2021-23885
Privilege escalation vulnerability in McAfee Web Gateway (MWG) prior to 9.2.8 allows an authenticated user to gain elevated privileges through the User Interface and execute commands on the appliance via incorrect improper neutralization of user input in the troubleshooting page.
https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-23885
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-23885
Remediation
To remediate this issue:

• Customers on the Controlled release branch 10.0.x: Update to 10.0.4.
• Customers on 9.2.x: Update to 9.2.8.
• Customers on 8.2.x: Upgrade to 9.2.8 or update to 8.2.17.

Go to the Product Downloads site, and download the applicable product update file:

Product

Version

Type

Release Date

MWG

10.0.4

Update (Controlled release)

February 15, 2021

MWG

9.2.8

Update

February 15, 2021

MWG

8.2.17

Update

February 15, 2021

Download and Installation Instructions
For instructions to download McAfee product updates and hotfixes, see: KB56057 - How to download Enterprise product updates and documentation. Review the Release Notes and the Installation Guide for instructions on how to install these updates. All documentation is available at https://docs.mcafee.com.
Frequently Asked Questions (FAQs)
How do I know if my McAfee product is vulnerable or not?

For Appliances:

Use the following instructions for Appliance-based products:

1. Open the Administrator’s User Interface (UI).
2. Click the About link. The product version displays.

What is CVSS?
CVSS, or Common Vulnerability Scoring System, is the result of the National Infrastructure Advisory Council’s effort to standardize a system of assessing the criticality of a vulnerability. This system offers an unbiased criticality score between 0 and 10 that customers can use to judge how critical a vulnerability is and plan accordingly. For more information, visit the CVSS website at: https://www.first.org/cvss/.

When calculating CVSS scores, McAfee has adopted a philosophy that fosters consistency and repeatability. Our guiding principle for CVSS scoring is to score the exploit under consideration by itself. We consider only the immediate and direct impact of the exploit under consideration. We do not factor into a score any potential follow-on exploits that might be made possible by the successful exploitation of the issue being scored.

What are the CVSS scoring metrics?

CVE-2021-23885: Privilege escalation vulnerability in MWG

Base Score

9.0

Attack Vector (AV)

Network (N)

Attack Complexity (AC)

Low (L)

Privileges Required (PR)

Low (L)

User Interaction (UI)

Required ®

Scope (S)

Changed ©

Confidentiality ©

High (H)

Integrity (I)

High (H)

Availability (A)

High (H)

Temporal Score (Overall)

8.3

Exploitability (E)

Proof of Concept §

Remediation Level (RL)

Official Fix (O)

Report Confidence (RC)

Confirmed ©

NOTE: The below CVSS version 3.1 vector was used to generate this score.
https://nvd.nist.gov/vuln-metrics/cvss/v3-calculator?vector=AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H/E:P/RL:O/RC:C&version=3.1

Where can I find a list of all Security Bulletins?
All Security Bulletins are published on our external PSIRT website at https://www.mcafee.com/us/threat-center/product-security-bulletins.aspx. To see Security Bulletins for McAfee Enterprise products on this website click Enterprise Security Bulletins. Security Bulletins are retired (removed) once a product is both End of Sale and End of Support (End of Life).

How do I report a product vulnerability to McAfee?
If you have information about a security issue or vulnerability with a McAfee product, visit the McAfee PSIRT website for instructions at https://www.mcafee.com/us/threat-center/product-security-bulletins.aspx. To report an issue, click Report a Security Vulnerability.

How does McAfee respond to this and any other reported security flaws?
Our key priority is the security of our customers. If a vulnerability is found within any McAfee software or services, we work closely with the relevant security software development team to ensure the rapid and effective development of a fix and communication plan.

McAfee only publishes Security Bulletins if they include something actionable such as a workaround, mitigation, version update, or hotfix. Otherwise, we would simply be informing the hacker community that our products are a target, putting our customers at greater risk. For products that are updated automatically, a non-actionable Security Bulletin might be published to acknowledge the discoverer.

View our PSIRT policy on the McAfee PSIRT website at https://www.mcafee.com/us/threat-center/product-security-bulletins.aspx by clicking About PSIRT.
Resources
To contact Technical Support, log on to the ServicePortal and go to the Create a Service Request page at https://support.mcafee.com/ServicePortal/faces/serviceRequests/createSR:

• If you are a registered user, type your User ID and Password, and then click Log In.
• If you are not a registered user, click Register and complete the required fields. Your password and logon instructions will be emailed to you.

Disclaimer

The information provided in this Security Bulletin is provided as is without warranty of any kind. McAfee disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall McAfee or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if McAfee or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the preceding limitation may not apply.

Any future product release dates mentioned in this Security Bulletin are intended to outline our general product direction, and they should not be relied on in making a purchasing decision. The product release dates are for information purposes only, and may not be incorporated into any contract. The product release dates are not a commitment, promise, or legal obligation to deliver any material, code, or functionality. The development, release, and timing of any features or functionality described for our products remains at our sole discretion and may be changed or canceled at any time.