LiveActive security incident?Get immediate response
CVE Record

CVE-2023-43686: An issue was discovered in Malwarebytes 4.x and 5.x (and Nebula 2020-10-21 and later).

An issue was discovered in Malwarebytes 4.x and 5.x (and Nebula 2020-10-21 and later). A large number of Firefox preference files can cause the parser to ignore other browser configuration files, leading to a denial of service.

MediumCVSS 6.2Not KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

This issue can let a local condition disrupt Malwarebytes browser-configuration parsing. A large number of Firefox preference files may cause other browser configuration files to be ignored, creating an availability impact rather than data theft or tampering.

Executive priority

Treat this as a moderate operational-risk issue. It does not indicate data compromise, but it may reduce endpoint protection reliability. Remediate through normal vulnerability management, with priority for high-value systems and managed endpoint fleets.

Technical view

CVE-2023-43686 affects Malwarebytes 4.x and 5.x, plus Nebula 2020-10-21 and later. The parser can fail under excessive Firefox preference-file volume and ignore other browser configuration files. CVSS 3.1 is 6.2: local attack vector, low complexity, no privileges, no user interaction, availability impact only.

Likely exposure

Exposure is most relevant on endpoints running Malwarebytes 4.x or 5.x, or Nebula-managed deployments from 2020-10-21 onward. The supplied data does not provide a precise fixed-version matrix, CPE list, or platform breakdown.

Exploitation context

The source bundle does not show active exploitation, public exploit use, or KEV listing. The CVSS vector indicates local access is required, with no privileges or user interaction, and the impact is denial of service through availability loss.

Researcher notes

The evidence identifies CWE-755 and an availability-only parser failure. The supplied sources do not include root-cause detail, affected build numbers, fixed versions, or exploit evidence. Avoid assuming broader Malwarebytes products or remote exploitability without vendor confirmation.

Mitigation direction

  • Review the Malwarebytes advisory for fixed versions or supported workarounds.
  • Inventory Malwarebytes 4.x, 5.x, and Nebula-managed endpoint deployments.
  • Prioritize remediation where endpoint protection availability is operationally critical.
  • Monitor vendor channels for updated patch and version guidance.

Validation and detection

  • Confirm whether deployed Malwarebytes versions match the affected product ranges.
  • Check the vendor advisory for exact remediation status before closing findings.
  • Review endpoint security telemetry for Malwarebytes service or parser failures.
  • Verify security controls remain active after applying vendor-recommended updates.
Prepared
Confidence
medium
Sources
3

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

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · low confidence lookup

CWE-755: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. 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 lookup
cve · low confidence lookup

CVE-2023-43686 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
Medium
CVSS
6.2 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:L/AC:L/PR:N/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
3Timeline events
1ADP providers
2Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: partial

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
6.2CVSS 3.1MediumCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H2.53.6CISA-ADP

Vulnerability scoring details

Base CVSS 3.1 score

6.2Medium
CVSS 3.1 vector shape for CVE-2023-43686Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:L/AC:L/PR:N/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

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
cvssV3_1other:ssvc

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/an/an/aListed
Weakness

CWE details

CWE-755

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.