Security readout for executives and security teams
Plain-English summary
This is a local denial-of-service flaw in Webroot Secure Anywhere 21.4. A specially crafted executable can trigger an out-of-bounds read in a Webroot kernel driver, potentially crashing the affected system. The main business risk is endpoint disruption, not data theft or tampering, based on the provided CVSS metrics.
Executive priority
Prioritize remediation for systems where endpoint uptime matters or where users can run untrusted software. This is not described as a remote compromise or data breach issue, but a high-availability risk in security software installed broadly across endpoints.
Technical view
CVE-2021-40424 is a CWE-125 out-of-bounds read in WRCore_x64 handling of GetProcessCommand, B_03, or GetProcessCommandLine IOCTL requests. The CVSS 3.0 vector is local, low complexity, no privileges, no user interaction, changed scope, availability high impact, and no confidentiality or integrity impact.
Likely exposure
Exposure is likely limited to endpoints running Webroot Secure Anywhere 21.4 with the vulnerable WRCore_x64 driver. The attack path is local, requiring the attacker to run a crafted executable or otherwise issue the relevant IOCTL on the target system.
Exploitation context
The source bundle does not show CISA KEV listing or cited evidence of active exploitation. The described capability is local denial of service through driver IOCTL handling. Treat this as operationally important on managed endpoints, especially where untrusted local code execution is possible.
Researcher notes
Evidence is strongest for Webroot Secure Anywhere 21.4 only. The provided data names IOCTL GetProcessCommand, B_03, and GetProcessCommandLine in WRCore_x64. No patch version, proof of exploitation, or broader affected version range is provided in the source bundle.
Mitigation direction
- Inventory endpoints running Webroot Secure Anywhere 21.4.
- Check Webroot vendor guidance for fixed versions or supported remediation.
- Prioritize upgrade or removal of the affected version where confirmed.
- Monitor affected endpoints for driver crashes or unexpected reboots.
- Limit untrusted executable execution on systems awaiting remediation.
Validation and detection
- Confirm installed Webroot Secure Anywhere version on endpoint fleets.
- Verify whether WRCore_x64 is present on suspected affected systems.
- Review endpoint telemetry for crashes linked to Webroot driver activity.
- Check vulnerability management records for CVE-2021-40424 coverage.
- Document remediation status separately from exploit testing.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-125: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-40424 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.1 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H2.54Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
7.1HighVector: CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://talosintelligence.com/vulnerability_reports/TALOS-2021-1433CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Out-of-bounds Read
Out-of-bounds Read represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.