Vulnerability report

Exploited in the wild Confirmed confidence In CISA KEV

CVE-2021-21551

dbutil Denial of Service

Dell / dbutil · 2.3

Watch CVE-2021-21551 Browse KEV feed
Severity
CVSS 8.8 · High
Confidence
Confirmed
Exploit status
Exploited in the wild
EPSS
80.1%
First observed
—
Last observed
—

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2021-21551 is a vulnerability affecting Dell dbutil. Dell dbutil_2_3.sys driver contains an insufficient access control vulnerability which may lead to escalation of privileges, denial of service, or information...

Is it exploited?

Yes. Previdian tracks this CVE as a known exploited vulnerability. Confidence is confirmed. Listed in CISA KEV. Also confirmed by third-party sources.

Who is affected?

Dell / dbutil 2.3.

What should we do?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Overview

dbutil Denial of Service

Dell dbutil_2_3.sys driver contains an insufficient access control vulnerability which may lead to escalation of privileges, denial of service, or information disclosure. Local authenticated user access is required.

Dell Affected
dbutil
2.3
Published
04 May 2021
Exploitation Reported
31 Mar 2022
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None

Tags

cisa metasploit

CVE References

Exploitation evidence

Why Previdian marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

CISA

Recorded 31 Mar 2022

A trusted third party reported exploitation.

Proof of concept available

GitHub

Recorded 13 May 2021

Public scanner or PoC coverage increases practical exploitability.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the Previdian Pro API.

Learn about Pro API access
Source Added
CISA First 2022-03-31 00:00 UTC
The Hacker News 2026-10-02 17:31 UTC

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets
User-Agents
Callback hosts
0
0
0

Request targets and User-Agents available in Pro. Callback host details available in Enterprise.

Virtual patch status

No Previdian virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

Scanner Artifacts

Scanner and exploit-framework references linked to this CVE.

Scanner Reference Detected
Metasploit https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/windows/local/cve_2021_21551_dbutil_memmove.rb 28 Apr 2025

Risk and context

Severity, weaknesses, and research context

CVSS v3.1

8.8 High

Potential damage if exploited. Separate from whether attackers are using it.

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

EPSS

80.1%

Estimated chance of exploitation in the next 30 days. Previdian's warning comes from evidence, not this score.

Weaknesses

Exposed IOCTL with Insufficient Access Control CWE-782

Recent mention · The Hacker News

Dell CSM Flaws Enable Unauthenticated Admin Access and Root on Kubernetes Nodes

Ravie LakshmananOct 02, 2026Vulnerability / Cloud Security Dell has released security updates to address multiple critical security flaws in Dell Container Storage Modules (CSM) that could be exploited by bad actors to take over susceptible systems. The vulnerabilities are...

Read full advisory

All CVSS Scores

CVSS v3.1 8.8 High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

CVSS v2.0 4.6 Medium

AV:L/AC:L/Au:N/C:P/I:P/A:P

Potential Proof of Concepts

These PoCs are unverified and could contain malware. Use at your own risk.

mathisvickie/CVE-2021-21551

github · Created 2021-05-30 10:15:10 UTC · 56 stars · AI assessment 90%

arbitrary kernel read/write in dbutil_2_3.sys, Proof of Concept Local Privilege Escalation to nt authority/system

waldo-irc/CVE-2021-21551

github · Created 2021-05-13 13:23:38 UTC · 237 stars · AI assessment 90%

Exploit to SYSTEM for CVE-2021-21551

cve_2021_21551_dbutil_memmove

metasploit · Created Unknown

Metasploit module for CVE-2021-21551

Timeline

From disclosure to observed exploitation

  1. 17:31 UTC

    KEV confirmed by The Hacker News

    Exploitation attested by an external source

  2. 15:02 UTC

    Metasploit module available

    Exploit module available

  3. 00:00 UTC

    Added to CISA KEV

    Listed in the CISA Known Exploited Vulnerabilities catalog

  4. 13:23 UTC

    Public PoC available

    Public proof-of-concept code published

  5. 15:15 UTC

    CVE published

    Vulnerability disclosed publicly

  6. 00:00 UTC

    CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

Start 14-day Pro trial Read API docs
  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2021-21551

Sample API response 
{
  "cve_id": "CVE-2021-21551",
  "confidence": "Confirmed",
  "cvss_score": 8.8,
  "cvss_estimated": false,
  "epss_score": 0.80058,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}