Kernel privilege escalation via unrestricted IOCTL memory writes
Published May 4, 2021 · Updated Oct 21, 2025
Insufficient access control in Dell DBUtil 2.3 allows local users to gain kernel privileges through crafted driver IOCTL requests. The dbutil_2_3.sys device permits unprivileged callers to issue IOCTL 0x9B0C1EC8, whose handler passes attacker-controlled addresses and values to memmove for arbitrary kernel-memory reads and writes. A local authenticated account and the vulnerable driver present on Windows are required; successful exploitation enables privilege escalation, data disclosure or modification, or a system crash.
Summary
What happened
Insufficient access control in Dell DBUtil 2.3 allows local users to gain kernel privileges through crafted driver IOCTL requests. The dbutil_2_3.sys device permits unprivileged callers to issue IOCTL 0x9B0C1EC8, whose handler passes attacker-controlled addresses and values to memmove for arbitrary kernel-memory reads and writes. A local authenticated account and the vulnerable driver present on Windows are required; successful exploitation enables privilege escalation, data disclosure or modification, or a system crash.
The record
- CVE
- CVE-2021-21551
- Published
- May 4, 2021
- Updated
- Oct 21, 2025
- Vendor
- Dell
- Product
- DBUtil
- Classifications
- CWE-782, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- May 4, 2021CVE publishedPublication date reported by the CVE source.
- Oct 21, 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.
- Affected versionversion=2.3
What conditions does exploitation require?
What is affected?
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.
Weakness, pattern, technique
Public exploit references
- Dell DBUtil 2.3 IOCTL Memory Read-Write proof of conceptproof of concept · unverified
- Dell DBUtil 2.3 Arbitrary Write Privilege Escalation exploitfunctional · unverified
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Reported exploitation
- CISA Known Exploited Vulnerabilities catalog entryknown exploited catalog
Technologies
Your stack
See the directory against your own environment.
Your stack
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