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CVE Record

CVE-2021-2170: 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

This is a denial-of-service issue in Oracle MySQL Server’s optimizer affecting 8.0.23 and prior. A high-privileged attacker who can reach MySQL over the network could make the server hang or crash repeatedly. The documented impact is database availability, not data theft or data modification.

Executive priority

Prioritize during normal vulnerability remediation, faster for critical databases. The risk is service outage caused by an already privileged attacker, so urgency depends on database business criticality, exposure, and privilege hygiene.

Technical view

CVE-2021-2170 affects MySQL Server component Server: Optimizer. CVSS 3.1 is 4.9 with network access, low complexity, high privileges, no user interaction, and high availability impact. Successful exploitation can cause a complete denial of service. Oracle’s April 2021 CPU and Fedora and NetApp advisories are the cited remediation channels.

Likely exposure

Exposure is likely limited to MySQL Server 8.0.23 or earlier where privileged database accounts are usable from reachable networks or multiple protocols. Systems with remote administrative access, broad database network access, or shared privileged credentials deserve closer review.

Exploitation context

The source bundle does not show CISA KEV listing or active exploitation. The vulnerability is described as easily exploitable after a high-privileged attacker has network access. Treat it as a post-authenticated availability risk, not an unauthenticated takeover.

Researcher notes

The supplied data identifies availability-only impact and no CWE. Evidence does not include exploit details, affected fork behavior, or proof of active exploitation. Validate against Oracle, Fedora, and NetApp advisories rather than extending affected-product assumptions.

Mitigation direction

  • Apply Oracle’s April 2021 Critical Patch Update guidance for MySQL Server.
  • Apply Fedora package updates where Fedora-provided MySQL packages are used.
  • Review NetApp guidance for affected dependent or bundled products.
  • Restrict MySQL network access to trusted hosts and management paths.
  • Reduce and monitor high-privileged MySQL account use.

Validation and detection

  • Inventory MySQL Server versions and flag 8.0.23 or earlier.
  • Confirm Oracle CPU or downstream vendor updates are installed.
  • Review database accounts with high privileges and remote access.
  • Check network controls limiting access to MySQL protocols.
  • Monitor MySQL error logs for repeated hangs or crashes.
Prepared
Confidence
high
Sources
7

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-2021-2170 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
6Source 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-2021-2170Attack 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.