Cyber Resilience

CVE-2023-5632

DoS in Eclipse Mosquitto 2.0.5

DoS
Published
18 October 2023
Modified
25 June 2025
Patch / advisory
View advisory
CVSS Score v3.1 7.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0069 50th percentile
Risk Priority 58 floored blend · peak EPSS

Summary

CVE-2023-5632 is a high-severity Excessive Iteration (CWE-834) vulnerability in Eclipse Mosquitto. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Endpoint Denial of Service (T1499); ranked at the 50th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability Data

In Eclipse Mosquito before and including 2.0.5, establishing a connection to the mosquitto server without sending data causes the EPOLLOUT event to be added, which results excessive CPU consumption. This could be used by a malicious actor to perform denial…

more

of service type attack. This issue is fixed in 2.0.6

CWE(s)
CWE-834

Related Threats

MITRE ATT&CK Enterprise Techniques

T1499 Endpoint Denial of Service Impact
Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users.
attack.mitre.org →
T1499.003 Application Exhaustion Flood Impact
Adversaries may target resource intensive features of applications to cause a denial of service (DoS), denying availability to those applications.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-3592Same product: Eclipse Mosquitto
CVE-2023-28366Same product: Eclipse Mosquitto
CVE-2023-0809Same product: Eclipse Mosquitto
CVE-2024-8376Same product: Eclipse Mosquitto
CVE-2024-3935Same product: Eclipse Mosquitto
CVE-2024-10525Same product: Eclipse Mosquitto
CVE-2026-63252Same vendor: Eclipse
CVE-2023-4043Same vendor: Eclipse
CVE-2025-55181Shared CWE-834
CVE-2026-41313Shared CWE-834

Affected Assets

eclipse
mosquitto
2.0.5

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 2 hardening rules · 2 OS baselines
Validate
Prove the fix (OWASP ASVS)

—

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.PS-06 mostly match
prevents

Secure SDLC practices directly prevent unbounded loops via code review, static analysis, and testing.

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.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing can detect excessive iteration through stress and fuzz testing.

A.8.25 Secure development life cycle partial match
prevents

Secure development lifecycle requires input validation and loop bounds, directly limiting excessive iteration.

A.8.26 Application security requirements partial match
prevents

Application security requirements include resource-consumption limits that prevent unbounded loops.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture principles mandate defensive coding patterns such as loop termination checks.

A.8.28 Secure coding partial match
prevents

Secure coding standards explicitly forbid unbounded loops and require explicit iteration limits.

References