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CVE Record

CVE-2021-35577: 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 8.0.26 and prior. Easily exploitable vulnerability allows high privileged attacker with network access via MySQL Protcol 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-2021-35577 is a denial-of-service flaw in Oracle MySQL Server’s optimizer. A highly privileged user who can connect over the MySQL protocol could make the database hang or crash repeatedly, disrupting applications that depend on it.

Executive priority

Treat as a moderate operational risk. It is not described as data theft or privilege escalation, but repeated MySQL crashes can disrupt business services. Prioritize patching for production databases and environments with many privileged users or broad internal network access.

Technical view

Oracle describes this as an easily exploitable Server: Optimizer vulnerability affecting MySQL Server 8.0.26 and prior. The CVSS 3.1 score is 4.9, with network attack vector, low complexity, high privileges required, and high availability impact only.

Likely exposure

Exposure is most relevant where MySQL Server 8.0.26 or earlier is reachable by privileged database users or service accounts over the network. Internet exposure is not required, but broad internal access or shared administrative credentials increases operational risk.

Exploitation context

The provided sources do not show active exploitation, and the CVE is not marked KEV in the bundle. Exploitation requires high privileges and MySQL protocol access, so this is mainly an insider, compromised-admin, or compromised-service-account availability risk.

Researcher notes

The bundle does not provide CWE, proof of concept, or fixed-version details beyond vendor advisories. Analysis should stay focused on affected MySQL Server 8.0.26 and prior, high-privilege network access, and availability impact from optimizer-triggered hang or crash behavior.

Mitigation direction

  • Review Oracle’s October 2021 CPU guidance for the supported MySQL Server update path.
  • Apply relevant vendor or distribution MySQL updates, including downstream advisories where applicable.
  • Limit MySQL network access to trusted application and administration hosts.
  • Reduce and review highly privileged MySQL accounts and service credentials.
  • Prioritize critical databases where outages affect revenue or customer operations.

Validation and detection

  • Inventory MySQL Server deployments and identify versions 8.0.26 or earlier.
  • Confirm whether Oracle, Fedora, NetApp, or other vendor updates are applied.
  • Review privileged MySQL accounts with network login capability.
  • Check database uptime, crash, and hang logs for unexplained repeated availability events.
  • Verify firewall or security group rules restrict MySQL protocol access.
Prepared
Confidence
medium
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-2021-35577 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-2021-35577Attack 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 Server8.0.26 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.