CVE-2021-2440Network attack vector

Denial of service via undisclosed DML flaw

Published Jul 20, 2021 · Updated Sep 25, 2024

Denial of service in Oracle MySQL Server 8.0.25 and earlier allows remote authenticated users to hang or repeatedly crash the server. Oracle identifies the affected locus only as Server: DML and has not published the malformed statement or incorrect processing operation. Exploitation requires network access with high database privileges, and the documented consequence is limited to service availability.

CVSS severity4.9
Medium
EPSS probability1.72%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Denial of service in Oracle MySQL Server 8.0.25 and earlier allows remote authenticated users to hang or repeatedly crash the server. Oracle identifies the affected locus only as Server: DML and has not published the malformed statement or incorrect processing operation. Exploitation requires network access with high database privileges, and the documented consequence is limited to service availability.

The record

CVE
CVE-2021-2440
Published
Jul 20, 2021
Updated
Sep 25, 2024
Vendor
Oracle Corporation
Product
MySQL Server
Classifications
T1499
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Jul 20, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 25, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=8.0.25 and prior

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Oracle Corporation · MySQL Serverversion=8.0.25 and prior

Published CVSS scores

4.9Oracle CorporationCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo