CVE-2021-2399Network attack vector

Authenticated server hang or repeatable crash

Published Jul 20, 2021 · Updated Sep 26, 2024

Denial of service in MySQL Server 8.0.25 and earlier allows remote authenticated users with high privileges to hang or crash the server. Oracle identifies the affected locus only as the Server DDL component and has not disclosed the specific operation or input that triggers the failure. Exploitation requires a high-privileged MySQL account and network access over the MySQL protocol; the bounded consequence is a hang or frequently repeatable crash.

CVSS severity4.9
Medium
EPSS probability1.66%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in MySQL Server 8.0.25 and earlier allows remote authenticated users with high privileges to hang or crash the server. Oracle identifies the affected locus only as the Server DDL component and has not disclosed the specific operation or input that triggers the failure. Exploitation requires a high-privileged MySQL account and network access over the MySQL protocol; the bounded consequence is a hang or frequently repeatable crash.

The record

CVE
CVE-2021-2399
Published
Jul 20, 2021
Updated
Sep 26, 2024
Vendor
Oracle Corporation
Product
MySQL Server
Classifications
T1499.004
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Jul 20, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 26, 2024Record 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.

  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.

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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

T1499.004Application or System Exploitation

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

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Your stack

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