Security readout for executives and security teams
Plain-English summary
Older Eclipse Mosquitto brokers may keep delivering a retained MQTT message even after the publisher loses access to that topic. In some systems, that stale retained message could trigger actions clients should no longer be able to cause. The source bundle does not provide CVSS, a patch version, or exploitation evidence.
Executive priority
Treat this as targeted hygiene for MQTT environments rather than an emergency based on the provided evidence. Prioritize review if Mosquitto controls devices, automation, or safety-relevant workflows and if retained messages are used with changing permissions.
Technical view
CVE-2018-12546 affects Eclipse Mosquitto 1.0 through 1.5.5 inclusive. The issue is access-control related: retained messages remain available to future subscribers after the original client’s topic access is revoked. The mapped weakness is CWE-284. No CVSS vector or detailed remediation is included in the provided sources.
Likely exposure
Exposure is most likely where Eclipse Mosquitto 1.0-1.5.5 is deployed, retained MQTT messages are used, and topic permissions can change after publication. Systems using retained messages to drive device or workflow behavior have higher business relevance.
Exploitation context
The provided sources do not report active exploitation, and this CVE is not marked KEV. Abuse would depend on prior ability to publish a retained message and later permission revocation. The sources do not provide exploit details or observed attacks.
Researcher notes
Evidence is limited to the CVE description and Eclipse bug reference. The key condition is retained message persistence after authorization changes. Validate behavior without publishing operationally harmful content. Do not assume all Mosquitto deployments are exposed; retained-message and ACL-change patterns matter.
Mitigation direction
- Inventory Mosquitto brokers and flag versions 1.0 through 1.5.5.
- Check Eclipse Mosquitto guidance for fixed versions or supported remediation.
- Review retained-message use where topic ACLs are changed after publication.
- Clear retained messages tied to revoked access using vendor-supported procedures.
- Assess business workflows where retained messages can trigger operational effects.
Validation and detection
- Confirm broker versions across production, staging, and embedded deployments.
- Identify topics using retained messages and changing access controls.
- Review ACL revocation workflows for retained-message cleanup expectations.
- Test in a controlled environment whether revoked publishers’ retained messages remain deliverable.
- Document affected topics, clients, and operational consequences before remediation.
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.
CWE-284: Authorization and privilege behavior lookup
Authorization weaknesses can support privilege escalation and valid-account review, depending on exploit path. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2018-12546 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
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
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 and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://bugs.eclipse.org/bugs/show_bug.cgi?id=543127CVE 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.
Improper Access Control
Improper Access Control represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.