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CVE Record

CVE-2020-2921: Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Group Replication Plugin).

Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Group Replication Plugin). Supported versions that are affected are 8.0.19 and prior. Difficult to exploit 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 3.0 Base Score 4.4 (Availability impacts). CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H).

MediumCVSS 4.4Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2020-2921 is a MySQL Server flaw in the Group Replication Plugin affecting supported versions 8.0.19 and earlier. A highly privileged network attacker could trigger a hang or repeatedly crash MySQL, causing a complete denial of service. It does not report data theft or data modification impact.

Executive priority

Treat as a scheduled remediation item for production MySQL environments, not an emergency based on current evidence. Prioritize clustered or replicated databases where downtime would disrupt revenue, operations, or customer-facing services.

Technical view

Oracle describes a difficult-to-exploit availability vulnerability in MySQL Server Group Replication Plugin. The CVSS 3.0 vector is AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H, scoring 4.4. The attacker requires high privileges and network access over multiple protocols. Successful exploitation affects availability only.

Likely exposure

Exposure is most relevant to organizations running MySQL Server 8.0.19 or earlier, especially where Group Replication is deployed and highly privileged accounts can connect over the network. Internet exposure is not required, but broad internal database access increases operational risk.

Exploitation context

The provided bundle does not show CISA KEV listing or active exploitation. The vulnerability is rated difficult to exploit and requires high privileges. Practical risk is mainly insider, compromised administrator, or chained access causing database downtime.

Researcher notes

Evidence is limited to vendor and distribution advisories plus the CVE record. No CWE, proof of concept, or exploit details are provided. Analysis should avoid assumptions about affected forks, exact fixed versions, or exploitability beyond Oracle’s stated high privilege and high complexity requirements.

Mitigation direction

  • Apply Oracle April 2020 CPU guidance or supported vendor package updates.
  • Check Ubuntu, Fedora, Gentoo, or NetApp advisories if using their packages or appliances.
  • Reduce MySQL administrative access to trusted hosts and required operators only.
  • Review whether Group Replication is required and follow vendor guidance for configuration changes.

Validation and detection

  • Inventory MySQL Server instances and identify versions 8.0.19 or earlier.
  • Confirm whether the Group Replication Plugin is installed or enabled.
  • Verify installed packages include the relevant Oracle or distribution security update.
  • Review MySQL logs and monitoring for unexplained hangs or repeated crashes.
  • Confirm CISA KEV status remains absent before stating active exploitation.
Prepared
Confidence
high
Sources
9

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-2020-2921 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
4.4 (3.0)
Known Exploited
No
Published

Vector: CVSS:3.0/AV:N/AC:H/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
8Source 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
4.4CVSS 3.0MediumCVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H0.73.6Primary CVE score

Vulnerability scoring details

Base CVSS 3.0 score

4.4Medium
CVSS 3.0 vector shape for CVE-2020-2921Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.0/AV:N/AC:H/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 Server8.0.19 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.