CVE-2021-40425

Windows crash via malformed IOCTL_B03 request

Published Apr 14, 2022 · Updated Apr 15, 2025

Out-of-bounds read in Webroot SecureAnywhere 21.4 allows local users to crash Windows via a malformed IOCTL_B03 request. The WRCore_x64 driver dereferences an invalid buffer-derived pointer at offset 0x20 without validating the request data, accessing unmapped kernel memory. A local executable that can open the driver's symbolic link and issue DeviceIoControl can trigger a blue-screen system crash.

CVSS severity6.5
Medium
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 Webroot SecureAnywhere 21.4 allows local users to crash Windows via a malformed IOCTL_B03 request. The WRCore_x64 driver dereferences an invalid buffer-derived pointer at offset 0x20 without validating the request data, accessing unmapped kernel memory. A local executable that can open the driver's symbolic link and issue DeviceIoControl can trigger a blue-screen system crash.

The record

CVE
CVE-2021-40425
Published
Apr 14, 2022
Updated
Apr 15, 2025
Vendor
Webroot
Product
Webroot SecureAnywhere
Classifications
CWE-125, T1529
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?

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  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

4.9NIST NVDAV:L/AC:L/Au:N/C:N/I:N/A:C
6.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
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.

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1529System Shutdown/Reboot

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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