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CVE Record

CVE-2021-2444: Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Optimizer).

Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Optimizer). Supported versions that are affected are 8.0.23 and prior. Easily exploitable vulnerability allows high privileged attacker with network access via multiple protocols to compromise MySQL Server. Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of MySQL Server. CVSS 3.1 Base Score 4.9 (Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H).

MediumCVSS 4.9Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2021-2444 is a MySQL Server Optimizer flaw that can let a highly privileged network user make MySQL hang or crash repeatedly. It is not described as data theft or privilege escalation; the business risk is database downtime for MySQL 8.0.23 or earlier.

Executive priority

Treat this as a reliability risk, not a broad compromise risk. Prioritize patching business-critical MySQL databases and any network-reachable legacy instances, especially where privileged credentials are broadly shared or weakly governed.

Technical view

Oracle describes the issue in MySQL Server: Optimizer, affecting supported MySQL Server 8.0.23 and prior. CVSS 4.9 reflects network access, low attack complexity, no user interaction, but high privileges required. Impact is availability only, with complete denial of service through hangs or repeatable crashes.

Likely exposure

Most exposure is in environments where MySQL 8.0.23 or earlier remains reachable by users or services with high database privileges. Internet exposure increases operational risk, but the source evidence still requires high privileges.

Exploitation context

The provided sources do not show CISA KEV listing or active exploitation. The issue is described as easily exploitable once a high-privileged attacker has network access via supported MySQL protocols.

Researcher notes

The public description names the Optimizer component but does not provide root-cause details, exploit mechanics, or specific fixed version text in the supplied bundle. Analysis should stay bounded to Oracle’s affected range and availability-only impact.

Mitigation direction

  • Apply the relevant Oracle July 2021 Critical Patch Update or later supported MySQL security update.
  • Upgrade MySQL Server instances running 8.0.23 or earlier where vendor guidance confirms exposure.
  • Restrict network access to MySQL to trusted application hosts and administrative networks.
  • Review and reduce high-privileged MySQL accounts to the minimum operational need.
  • Check NetApp guidance if MySQL is present through NetApp-supported products or integrations.

Validation and detection

  • Inventory MySQL Server versions and flag 8.0.23 or earlier.
  • Confirm whether Oracle July 2021 CPU or later MySQL security fixes are installed.
  • Identify MySQL instances reachable over networks by high-privileged users or services.
  • Review database crash, restart, and hang history around exposed MySQL instances.
  • Verify privileged account ownership, necessity, and recent activity.
Prepared
Confidence
high
Sources
4

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

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CVE-2021-2444 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
4.9 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
0Timeline events
0ADP providers
3Source links

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
4.9CVSS 3.1MediumCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H1.23.6Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

4.9Medium
CVSS 3.1 vector shape for CVE-2021-2444Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
Oracle CorporationMySQL Server8.0.23 and priorListed
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.