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CVE-2021-21551

From Exploited flaws, HARD’s guide to the flaws being used in attacks · Checked
This article is about a flaw in Dell dbutil Driver. For every flaw being used in attacks, see Exploited flaws.

CVE-2021-21551 is a security flaw in Dell dbutil Driver. Someone who already has a foothold can use Dell dbutil Driver to take full control of the machine. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 31 Mar 2022.[1]

Dell dbutil Driver is business software or equipment. Most families won’t have it, but attackers break into it to get inside companies, and from there to what those companies hold about their customers, patients and staff. Dell has published a fix or advice.

Description

CISA calls it an insufficient access control in Dell dbutil Driver. In its words: “Dell dbutil driver contains an insufficient access control vulnerability which may lead to escalation of privileges, denial-of-service (DoS), or information disclosure.”[1]

The CVE record adds: “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.”[2]

The underlying weakness is CWE-782, in MITRE’s list of common software weaknesses.

It scores 7.8 out of 10 on the Common Vulnerability Scoring System, which rates it high, scored by NVD using CVSS 3.1.[2]

Affected versions

NVD’s record doesn’t list version ranges for it; Dell’s advisory has them[3]. CISA names the product as Dell dbutil Driver.

Most families won’t have Dell dbutil Driver; it’s for whoever looks after IT at work.

Exploitation

CISA added it to its catalog of known exploited vulnerabilities on 31 Mar 2022, 331 days after it was made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 21 Apr 2022 to fix it.[1]

FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at 80%. That’s in the top 1% of the flaws it scores.[4]

CISA assesses it as not automatable: each attack takes some work.

CISA doesn’t say who was attacked, or how.

Fix

Dell has published a fix or advice.[3] CISA’s required action: “Apply updates per vendor instructions.”[1]

  1. Check whether you use it.Dell dbutil Driver is business software or equipment, so most families won’t have it. If you run a business, or work from home on company equipment, ask whoever looks after your IT.
  2. Send this page to your IT person.Ask them to confirm it’s fixed, or not in use. CISA gave US government agencies until 21 Apr 2022 to fix it.
  3. If it can’t be fixed, take it offline.CISA’s advice when there’s no fix is to stop using the product, or take it off the internet, until there is one.

You can’t fix someone else’s server, but you can watch for what follows a break-in like this: a breach notice, a password reset you didn’t ask for, or a scam message that knows things it shouldn’t. HARD watches for those for you and your family.

Timeline

DateEvent
The flaw is made public in the National Vulnerability Database, with a severity score of 7.8.[2]
CISA adds it to its catalog of flaws known to be used in attacks.[1]
CISA’s deadline for US government agencies to fix it.[1]
FIRST puts the odds of it being used in attacks in the next 30 days at 80%.[4]

See also

Other Dell flaws

  • CVE-2026-22769, Dell RecoverPoint for Virtual Machines (RP4VMs): use of hard-coded credentials ·

Added the same day

  • CVE-2022-26871, Trend Micro Apex Central: arbitrary file upload ·
  • CVE-2022-1040, Sophos Firewall: authentication bypass ·
  • CVE-2021-34484, Microsoft Windows: user profile service privilege escalation ·
  • CVE-2021-28799, QNAP Network Attached Storage (NAS): NAS improper authorization ·
  • CVE-2018-10562, Dasan Gigabit Passive Optical Network (GPON) Routers: GPON routers command injection ·

References

  1. ^ Cybersecurity and Infrastructure Security Agency. “Dell dbutil Driver Insufficient Access Control Vulnerability”. Known Exploited Vulnerabilities Catalog, added 31 Mar 2022.
  2. ^ National Institute of Standards and Technology. “CVE-2021-21551 Detail”. National Vulnerability Database, published 4 May 2021.
  3. ^ Dell. Advisories and fixes: dell.com.
  4. ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.796, percentile 99.6, 31 Oct 2026.
  5. CVE Program. “CVE-2021-21551”. The official CVE record.

This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.