LiveActive security incident?Get immediate response
CVE Record

CVE-2021-2342: 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 5.7.34 and prior and 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

CVE-2021-2342 is a denial-of-service issue in Oracle MySQL Server. A highly privileged user who can reach MySQL over the network could cause the server to hang or crash repeatedly, disrupting applications that depend on it.

Executive priority

Treat as a controlled remediation item for business-critical databases. It is not described as exploited, but successful abuse can cause complete database downtime.

Technical view

The flaw affects MySQL Server Optimizer in supported versions 5.7.34 and prior, and 8.0.25 and prior. CVSS is 4.9: network exploitable, low complexity, high privileges required, no user interaction, availability-only impact.

Likely exposure

Exposure is mainly MySQL Server instances at or below 5.7.34 or 8.0.25 where privileged database accounts can connect over network-accessible protocols.

Exploitation context

The source bundle does not show KEV listing or active exploitation evidence. Risk depends on whether attackers can obtain or misuse high-privilege MySQL credentials and reach the service.

Researcher notes

No CWE, trigger detail, proof of concept, or exploit path is provided in the bundle. Analysis should stay bounded to the Oracle-described Optimizer availability issue and CVSS vector.

Mitigation direction

  • Apply Oracle July 2021 CPU guidance or a later supported MySQL release.
  • Update vendor-packaged MySQL builds using relevant Fedora, NetApp, or platform advisories.
  • Restrict network access to MySQL from only trusted application and administration hosts.
  • Review and minimize high-privilege MySQL accounts and credential exposure.
  • Monitor MySQL crash, restart, and hang patterns until remediation is complete.

Validation and detection

  • Inventory MySQL Server versions across production and non-production systems.
  • Flag versions 5.7.34 and prior, and 8.0.25 and prior.
  • Confirm vendor package updates were applied where MySQL is delivered by a platform vendor.
  • Verify privileged MySQL accounts cannot connect from untrusted networks.
  • Review database availability monitoring for unexplained repeated crashes or hangs.
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-2021-2342 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-2021-2342Attack 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 Server5.7.34 and prior, 8.0.25 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.