LiveActive security incident?Get immediate response
CVE Record

CVE-2021-2367: 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 8.0.25 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
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

This is an availability vulnerability in Oracle MySQL Server 8.0.25 and earlier. An attacker who already has high privileges and network access can make the database hang or repeatedly crash. The business risk is service disruption, not data theft or data modification, based on the supplied CVSS and description.

Executive priority

Treat this as a service reliability risk for business-critical databases, especially where privileged access is broad or weakly monitored. It is not described as a confidentiality or integrity issue, but database downtime can still affect operations and customer-facing services.

Technical view

CVE-2021-2367 affects the MySQL Server Optimizer component. The CVSS vector is AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H, meaning remote network reachability is relevant, but exploitation requires high privileges. Successful exploitation causes complete denial of service through hangs or repeatable crashes.

Likely exposure

Exposure is most likely where MySQL Server 8.0.25 or earlier is reachable over network protocols by highly privileged database users. Systems running later vendor-fixed packages are less likely exposed, but the provided sources do not list exact fixed build numbers.

Exploitation context

The source bundle does not show CISA KEV listing or cited evidence of active exploitation. Exploitation is described as easy once the attacker has high privileges and network access, so insider misuse or compromised privileged database credentials are the main concern.

Researcher notes

No CWE is supplied. The key technical boundary is PR:H: a low-privileged or unauthenticated remote attacker is not indicated by the provided CVSS. Validation should focus on version exposure, privileged access paths, and whether vendor package updates have been applied.

Mitigation direction

  • Apply Oracle MySQL updates from the July 2021 Critical Patch Update guidance.
  • Update Fedora-managed MySQL packages using the referenced Fedora advisories where applicable.
  • Review NetApp advisory guidance if NetApp-managed environments are in scope.
  • Restrict MySQL network exposure to trusted administrative paths.
  • Reduce and monitor high-privilege database accounts.

Validation and detection

  • Inventory all MySQL Server instances and record exact versions.
  • Flag MySQL Server 8.0.25 and earlier for remediation review.
  • Confirm whether Oracle, Fedora, or NetApp advisory guidance applies to each instance.
  • Verify only authorized high-privilege users can reach MySQL over network protocols.
  • Review monitoring for unexplained MySQL hangs, restarts, or repeated crashes.
Prepared
Confidence
high
Sources
6

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

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cve · low confidence lookup

CVE-2021-2367 mapping review

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

Open ATT&CK lookup
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
5Source 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-2021-2367Attack 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 Server8.0.25 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.