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CVE Record

CVE-2021-2278: 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-2021-2278 is a MySQL Server Optimizer flaw that can let a highly privileged network attacker hang or repeatedly crash the database. The cited impact is outage only, not data theft or tampering. Business urgency depends on whether affected MySQL servers support critical services.

Executive priority

Treat as a moderate-priority availability risk. Prioritize systems where MySQL backs revenue, authentication, customer operations, or other time-sensitive workflows. The privilege requirement reduces likelihood, but a successful attack can still create a complete database outage.

Technical view

Oracle lists MySQL Server 8.0.23 and prior as affected. The CVSS 3.1 vector is AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H, scoring 4.9. Successful attack can cause complete denial of service through hangs or repeatable crashes.

Likely exposure

Likely exposure is MySQL Server 8.0.23 or earlier reachable by authenticated, high-privileged users over network protocols. Internet exposure matters less than who has privileged database access. NetApp also published an advisory, but this bundle does not detail NetApp-specific affected products.

Exploitation context

The bundle does not cite active exploitation, and KEV is false. Exploitation is described as easy once the attacker has high privileges and network access. The main operational concern is database availability disruption rather than confidentiality or integrity compromise.

Researcher notes

The source bundle provides product, version, CVSS vector, and denial-of-service impact, but no CWE, root-cause detail, proof of exploitation, or specific fixed version. Avoid assuming confidentiality or integrity impact. Validation should focus on version exposure, privilege pathways, and vendor patch status.

Mitigation direction

  • Review Oracle April 2021 CPU guidance for the supported MySQL fix path.
  • Upgrade affected MySQL Server instances according to vendor guidance.
  • Restrict privileged database accounts to trusted administrators and services.
  • Limit network access to MySQL management and application paths.
  • Review NetApp advisory if NetApp products may bundle or depend on MySQL.

Validation and detection

  • Inventory MySQL Server versions and flag 8.0.23 or earlier.
  • Identify privileged accounts with network access to each MySQL server.
  • Confirm vendor patch or upgrade status from Oracle guidance.
  • Check monitoring for unexplained MySQL hangs or repeated crashes.
  • Review NetApp advisory applicability in relevant environments.
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-2021-2278 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-2021-2278Attack 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.