CVE-2021-31842: Security Bulletin - Endpoint Security for Windows update fixes two vulnerabilities (CVE-2021-31843, CVE-2021-31842) and updates the cURL library

First Published: September 16, 2021

Product:

Impacted Versions:

CVE ID:

Impact of Vulnerabilities:

Severity Ratings:

CVSS v3.1
Base/Temporal Scores:

Endpoint Security (ENS) for Windows

Prior to 10.7.0 and 10.6.1 September 2021 Update

CVE-2021-31843

CWE-269: Improper Privileges Management

High

7.3 / 6.6

ENS for Windows

Prior to 10.7.0 and 10.6.1 September 2021 Update

CVE-2021-31842

CWE-611: XML External Entity Injection

Medium

5.0 / 4.5

ENS for Windows

Prior to 10.7.0 and 10.6.1 September 2021 Update

Numerous

Multiple against cURL library

Critical

Recommendations:

Install or update to ENS 10.7.0 and 10.6.1 September 2021 Update

Security Bulletin Replacement:

None

Location of updated software:

Product Downloads site

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Article contents:

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

Vulnerability Description
These releases address two issues in McAfee Enterprise owned code, and an update to cURL library. cURL is a third-party library used in the product and was updated from 7.22 to the latest. This update addresses multiple vulnerabilities, the highest of which are rated critical. You can find details of the issues addressed on the cURL website.

1. CVE-2021-31843
   Improper privileges management vulnerability in Endpoint Security (ENS) Windows prior to 10.7.0 September 2021 Update allows local users to access files which they would otherwise not have access to via manipulating junction links to redirect McAfee folder operations to an unintended location.
   NVD CVE-2021-31843
   MITRE CVE-2021-31843

2. CVE-2021-31842
   XML Entity Expansion injection vulnerability in Endpoint Security (ENS) for Windows prior to 10.7.0 September 2021 Update allows a local user to initiate high CPU and memory consumption resulting in a Denial of Service attack through carefully editing the file and then executing the setup process.
   NVD CVE-2021-31842
   MITRE CVE-2021-31842

Remediation
To remediate these issues:

• Customers on ENS 10.7.0 should update to ENS 10.7.0 September 2021 Update.
• Customers on ENS 10.6.1 should upgrade to ENS 10.7.0 September 2021 Update, or update to ENS 10.6.1 September 2021 Update.

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

Product

Version

Type

Release Date

ENS for Windows

10.7.0 September 2021 Update
10.6.1 September 2021 Update

Update

September 16, 2021

Download and Installation Instructions
For instructions to download 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 on the Product Documentation site.
Frequently Asked Questions (FAQs)
How do I know if my product is vulnerable or not?

For Endpoint Security on Windows:

Use the following instructions for endpoint or client-based products:

1. Right-click the McAfee tray shield icon on the Windows taskbar.
2. Select McAfee Endpoint Security.
3. In the console, select Action Menu.
4. In the Action Menu, select About. The product version displays.

What is CVSS?
Common Vulnerability Scoring System (CVSS) 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.

When calculating CVSS scores, we’ve 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 don’t 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?

1. CVE-2021-31843: Improper access control vulnerability in ENS for Windows

**Base Score**

**7.3**

Attack Vector (AV)

Local (L)

Attack Complexity (AC)

Low (L)

Privileges Required (PR)

Low (L)

User Interaction (UI)

Required (R)

Scope (S)

Unchanged (U)

Confidentiality (C)

High (H)

Integrity (I)

High (H)

Availability (A)

High (H)

**Temporal Score (Overall)**

**6.6**

Exploitability (E)

Proof-of-Concept (P)

Remediation Level (RL)

Official Fix (O)

Report Confidence (RC)

Confirmed (C)

   
**NOTE:** This CVSS version 3.1 vector was used to generate this score.  

2. CVE-2021-31842: XML Entity expansion vulnerability in ENS for Windows

**Base Score**

**5.0**

Attack Vector (AV)

Local (L)

Attack Complexity (AC)

Low (L)

Privileges Required (PR)

Low (L)

User Interaction (UI)

Required (R)

Scope (S)

Unchanged (U)

Confidentiality (C)

None (N)

Integrity (I)

None (N)

Availability (A)

High (H)

**Temporal Score (Overall)**

**4.5**

Exploitability (E)

Proof-of-Concept (P)

Remediation Level (RL)

Official Fix (O)

Report Confidence (RC)

Confirmed (C)

   
**NOTE:** This CVSS version 3.1 vector was used to generate this score.

Where can I find a list of all Security Bulletins?
All Security Bulletins are published on our Knowledge Center. 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 you?
If you have information about a security issue or vulnerability with a product, follow the instructions provided in KB95563 - Report a vulnerability.

How do you 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 of our 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.

We only publish 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.

To view our PSIRT policy, see KB95564 - About PSIRT.

Resources

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Disclaimer
The information provided in this Security Bulletin is provided as is without warranty of any kind. We disclaim all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall we or our suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits, or special damages, even if we or our suppliers have been advised of the possibility of such damages. Some states don’t 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 shouldn’t 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 aren’t 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 remain at our sole discretion and may be changed or canceled at any time.