CVE-2021-40424

System crash via undersized IOCTL buffer

Published Apr 14, 2022 · Updated Apr 15, 2025

Out-of-bounds read in WRCore_x64 in Webroot SecureAnywhere 21.4 allows local users to crash Windows through a crafted IOCTL request. The GetProcessCommandLine handler accepts 0x18-byte input buffers, then reads the hprocess field at offset 0x24 from the user-controlled buffer. The trigger requires a locally executed program with access to the driver device; successful exploitation causes a Windows system crash.

CVSS severity7.1
High
EPSS probability0.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in WRCore_x64 in Webroot SecureAnywhere 21.4 allows local users to crash Windows through a crafted IOCTL request. The GetProcessCommandLine handler accepts 0x18-byte input buffers, then reads the hprocess field at offset 0x24 from the user-controlled buffer. The trigger requires a locally executed program with access to the driver device; successful exploitation causes a Windows system crash.

The record

CVE
CVE-2021-40424
Published
Apr 14, 2022
Updated
Apr 15, 2025
Vendor
Webroot
Product
Webroot SecureAnywhere
Classifications
CWE-125, T1499.004
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 14, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 15, 2025Record 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=21.4

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Webroot · Webroot SecureAnywhereversion=21.4

Published CVSS scores

7.1Cisco TalosCVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

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.

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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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1499.004Application or System Exploitation

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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