CVE-2021-31842

Local denial of service via XML entity expansion

Published Sep 17, 2021 · Updated Aug 3, 2024

XML entity expansion in McAfee Endpoint Security for Windows before 10.7.0 September 2021 Update allows local users to cause denial of service. The setup process parses a carefully edited EPDeploy.xml file and recursively expands XML entities until CPU and memory are exhausted. A low-privileged local user must modify the deployment file and cause setup to process it; the bounded consequence is resource exhaustion and service interruption.

CVSS severity5.5
Medium
EPSS probability0.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

XML entity expansion in McAfee Endpoint Security for Windows before 10.7.0 September 2021 Update allows local users to cause denial of service. The setup process parses a carefully edited EPDeploy.xml file and recursively expands XML entities until CPU and memory are exhausted. A low-privileged local user must modify the deployment file and cause setup to process it; the bounded consequence is resource exhaustion and service interruption.

The record

CVE
CVE-2021-31842
Published
Sep 17, 2021
Updated
Aug 3, 2024
Vendor
McAfee
Product
McAfee Endpoint Security for Windows
Classifications
CWE-776, CAPEC-197, T1499.003
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 17, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <10.7.0 September 2021 Update

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

McAfee · McAfee Endpoint Security for Windowsversion=unspecified <10.7.0 September 2021 Update

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.0TrellixCVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H
2.1NIST NVDAV:L/AC:L/Au:N/C:N/I:N/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-776Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')
CAPEC-197Exponential Data Expansion
T1499.003Endpoint Denial of Service: Application Exhaustion Flood

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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