Security readout for executives and security teams
Plain-English summary
CVE-2021-35642 can let a highly privileged remote user make affected MySQL Server instances hang or crash repeatedly. The business impact is service availability, not data theft or data modification based on the supplied sources.
Executive priority
Treat as a scheduled remediation item unless the database supports critical operations or broad privileged access exists. Prioritize patching exposed or high-availability MySQL systems first.
Technical view
Oracle describes a MySQL Server Optimizer vulnerability affecting supported versions 8.0.26 and prior. It is network reachable, low complexity, requires high privileges, and needs no user interaction. Successful exploitation can cause complete denial of service through hangs or frequent repeatable crashes.
Likely exposure
Exposure is limited to MySQL Server 8.0.26 and prior where high-privileged users can connect over network-accessible MySQL protocols.
Exploitation context
The bundle does not show CISA KEV listing or cited active exploitation. Risk is constrained by the high-privilege requirement, but availability impact may matter for business-critical databases.
Researcher notes
No CWE is supplied in the bundle. Oracle identifies the affected component as Server: Optimizer and the CVSS vector as AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H. The available evidence supports denial-of-service impact only.
Mitigation direction
- Apply Oracle's October 2021 Critical Patch Update guidance for MySQL Server.
- Check NetApp guidance if MySQL is present through NetApp-supported products or appliances.
- Restrict network access to MySQL services to trusted administrative paths.
- Review and minimize high-privileged MySQL accounts.
Validation and detection
- Inventory MySQL Server deployments and flag versions 8.0.26 and prior.
- Confirm whether exposed instances accept network connections from high-privileged users.
- Verify patch status against Oracle's October 2021 CPU guidance.
- Review availability monitoring for unexplained MySQL hangs or repeated crashes.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
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-2021-35642 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- 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
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.
CVSS vector scores
1 official scoreWe 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.
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H1.23.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
4.9MediumVector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://www.oracle.com/security-alerts/cpuoct2021.htmlCVE reference · x_refsource_MISC
- https://security.netapp.com/advisory/ntap-20211022-0003/CVE reference · x_refsource_CONFIRM
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.