Cyber Resilience

CVE-2025-21543

DoS in Oracle Mysql Cluster 7.6.0 – 7.6.32

Published
21 January 2025
Modified
03 November 2025
Patch / advisory
CVSS Score v3.1 4.9
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0085 55th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2025-21543 is a medium-severity Allocation of Resources Without Limits or Throttling (CWE-770) vulnerability in Oracle Mysql Cluster. Its CVSS base score is 4.9 (Medium).

Operationally, ranked in the top 45% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SC-5 (Denial-of-service Protection) and SC-6 (Resource Availability) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Packaging). Supported versions that are affected are 8.0.40 and prior, 8.4.3 and prior and 9.1.0 and prior. Easily exploitable vulnerability allows high privileged attacker with network access via multiple…

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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).

CWE(s)

Related Threats

CVEs Like This One

CVE-2025-21518Same product: Oracle Mysql Cluster
CVE-2025-21531Same product: Oracle Mysql Cluster
CVE-2026-60331Same product: Oracle Mysql Cluster
CVE-2026-46936Same product: Oracle Mysql Cluster
CVE-2026-47012Same product: Oracle Mysql Cluster
CVE-2026-61108Same product: Oracle Mysql Cluster
CVE-2026-60189Same product: Oracle Mysql Cluster
CVE-2026-60174Same product: Oracle Mysql Cluster
CVE-2026-60178Same product: Oracle Mysql Cluster
CVE-2025-21525Same product: Oracle Mysql Server

Affected Assets

oracle
mysql cluster
7.6.0 — 7.6.32 · 8.0.0 — 8.0.40 · 8.4.0 — 8.4.3
oracle
mysql server
8.0.0 — 8.0.40 · 8.4.0 — 8.4.3 · 9.0.0 — 9.1.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SC-5 Denial-of-service Protection
  • SC-6 Resource Availability
  • AC-6 Least Privilege
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 5 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V15.4.4

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly requires mechanisms to protect against or limit the effects of DoS attacks that exhaust server resources, matching the CWE-770 availability impact.

prevent

Requires the system to manage and allocate resources so that a high-privileged network attacker cannot induce hangs or crashes via unbounded allocation.

prevent

Limits the set of high-privileged accounts that can reach the vulnerable packaging component over the network, reducing the attack surface for this specific flaw.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.IR-04 mostly match
degrades

Monitoring capacity and taking action to maintain availability directly reduces unchecked resource allocation.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

detects

Baseline comparison of CPU, memory and bandwidth usage helps surface uncontrolled resource allocations before they cause service degradation.

prevents

Capacity projections and elasticity measures ensure that allocation requests are bounded and can be throttled, reducing the window in which an attacker can force unbounded resource reservations.

mitigates

Defining retention periods and deletion schedules for backup copies prevents indefinite accumulation of data on storage media without corresponding resource-management controls.

mitigates

Architectural redundancy and automatic failover limit the impact of an attacker who forces excessive allocations, because spare capacity can absorb the load until the primary instance recovers.

none

Documented incident response procedures that include activation of continuity plans and controlled recovery help ensure that resource consumption triggered by an incident is bounded and managed rather than left unbounded.

none

Mandating tested continuity procedures that preserve or replace resource-limiting controls prevents an attacker from exploiting the absence of throttling mechanisms during an outage.

References