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CVE Record

CVE-2021-3670: MaxQueryDuration not honoured in Samba AD DC LDAP

MaxQueryDuration not honoured in Samba AD DC LDAP

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2021-3670 is a resource-consumption issue in Samba AD DC LDAP where MaxQueryDuration is not enforced. Affected domain controllers may allow LDAP work to run longer than intended, potentially impacting availability. The public bundle does not provide CVSS scoring, fixed release numbers, or evidence of active exploitation.

Executive priority

Treat as a moderate availability risk for Samba-backed domain services. Prioritize environments where Samba AD DC supports authentication or directory services for business-critical systems, especially if LDAP is broadly reachable.

Technical view

The CVE describes Samba 4.1 and newer as affected when operating AD DC LDAP. The failure is that MaxQueryDuration is not honored, mapped to CWE-400. The source bundle links Samba fixes and a Gentoo advisory, but does not include complete scoring, exploit prerequisites, or explicit fixed-version ranges.

Likely exposure

Exposure is most relevant to organizations running Samba 4.1 or newer as an Active Directory Domain Controller with LDAP reachable by users, applications, or network peers. File-server-only Samba deployments are not identified as affected in the provided bundle.

Exploitation context

The provided sources do not state active exploitation, and CISA KEV status is false. The described impact is availability-oriented: LDAP queries may exceed intended duration controls. The bundle does not specify whether authentication is required or whether exploitation is remote.

Researcher notes

Evidence is incomplete. The CVE title and description identify MaxQueryDuration enforcement failure in Samba AD DC LDAP, with CWE-400 and multiple Samba commits. Public bundle data does not provide CVSS, exploit maturity, authentication requirements, or fixed release mapping.

Mitigation direction

  • Inventory Samba AD DC deployments running Samba 4.1 or newer.
  • Check Samba, Red Hat, Gentoo, or distribution guidance for fixed packages.
  • Apply vendor-provided Samba updates where available.
  • Restrict LDAP access to trusted networks and required clients.
  • Monitor AD DC LDAP load and resource exhaustion symptoms.

Validation and detection

  • Confirm whether Samba is deployed as an AD Domain Controller.
  • Record installed Samba versions and package sources.
  • Review vendor advisories for CVE-2021-3670 fixed-version guidance.
  • Verify LDAP exposure from internal, partner, and untrusted networks.
  • Check operational logs for unusually long or resource-heavy LDAP activity.
Prepared
Confidence
medium
Sources
12

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-400: 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.

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cve · low confidence lookup

CVE-2021-3670 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
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.

0CVSS vectors
0Timeline events
0ADP providers
11Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/asambaAffects Samba 4.1 and newer.Listed
Weakness

CWE details

CWE-400

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

CWE-400 · source CWE mapping

Uncontrolled Resource Consumption

Uncontrolled Resource Consumption represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs