Cyber Resilience

CVE-2021-21551

Dell Dbutil ≤ 2.3

CISA KEVActive ExploitationEUVD ExploitedPublic PoC
Published
04 May 2021
Modified
28 October 2025
KEV Added
31 March 2022
Patch / advisory
CVSS Score v3.1 8.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
EPSS Score 0.53 99th percentile
Risk Priority 87 floored blend · peak EPSS

Summary

CVE-2021-21551 is a high-severity Exposed IOCTL with Insufficient Access Control (CWE-782) vulnerability in Dell Dbutil. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 1% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog; a public proof-of-concept is referenced.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

The vulnerability is an insufficient access control flaw, tracked as CVE-2021-21551, in the Dell dbutil_2_3.sys driver. It is assigned CWE-782 and carries a CVSS 3.1 base score of 8.8 with the vector AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H. The affected component is a kernel-mode driver distributed with multiple Dell client platforms.

A local authenticated user can send specially crafted IOCTL requests to the driver, enabling arbitrary kernel memory read and write operations. Successful exploitation can result in privilege escalation to kernel level, denial of service through system crashes, or disclosure of sensitive kernel memory contents.

Dell’s DSA-2021-088 advisory describes the issue and directs customers to install the updated driver versions provided in the security update package. Public proof-of-concept code demonstrating both memory read/write primitives and privilege-escalation chains has been published on Packet Storm.

EU & UK References

Vulnerability Data

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.

CWE(s)
KEV Date Added
31 March 2022

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1548 Abuse Elevation Control Mechanism Privilege Escalation
Adversaries may circumvent mechanisms designed to control privilege elevation to gain higher-level permissions.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-22769Same vendor: Dellboth on KEV
CVE-2023-32494Same vendor: Dell
CVE-2023-28046Same vendor: Dell
CVE-2026-32655Same vendor: Dell
CVE-2023-28047Same vendor: Dell
CVE-2023-28041Same product: Dell Alienware M15 R4
CVE-2023-28029Same product: Dell Alienware M15 R4
CVE-2023-28056Same product: Dell Alienware M15 R4
CVE-2023-28027Same product: Dell Alienware M15 R4
CVE-2023-28052Same product: Dell Alienware M15 R4

Affected Assets

dell
dbutil
≤ 2.3

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V8.2.1

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.AA-05 full match
prevents

Directly enforces least-privilege access permissions on interfaces such as IOCTLs.

PR.IR-01 mostly match
prevents

Protects environments from unauthorized logical access, which includes improperly exposed IOCTL entry points.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing can detect missing IOCTL authorization during development.

prevents

Privileged access rights directly restrict who may invoke sensitive IOCTLs.

prevents

Secure development lifecycle includes design-time access-control requirements for device interfaces.

prevents

Application security requirements capture the need for proper IOCTL authorization.

prevents

Secure system architecture principles mandate least-privilege access to kernel interfaces.

prevents

Secure coding practices prevent omission of access-control checks on IOCTL handlers.

References