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CVE Record

CVE-2019-20925: Denial of service via malformed network packet

An unauthenticated client can trigger denial of service by issuing specially crafted wire protocol messages, which cause the message decompressor to incorrectly allocate memory. This issue affects MongoDB Server v4.2 versions prior to 4.2.1; MongoDB Server v4.0 versions prior to 4.0.13; MongoDB Server v3.6 versions prior to 3.6.15 and MongoDB Server v3.4 versions prior to 3.4.24.

HighCVSS 7.5Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

This flaw lets an unauthenticated network client crash or exhaust MongoDB Server availability using malformed protocol messages. It does not indicate data theft or tampering, but it can interrupt applications that depend on vulnerable MongoDB versions.

Executive priority

Prioritize remediation for internet-facing or broadly reachable MongoDB services. Treat this as an availability risk that can disrupt dependent applications, not as a confidentiality breach based on current evidence.

Technical view

CVE-2019-20925 is a MongoDB Server denial-of-service issue in the message decompressor, where malformed wire protocol messages can trigger incorrect memory allocation. CVSS 3.1 is 7.5, network exploitable, low complexity, no privileges, availability-only impact.

Likely exposure

Exposure is most likely where MongoDB Server 3.4, 3.6, 4.0, or 4.2 is reachable by untrusted clients and remains below the fixed maintenance releases named by MongoDB.

Exploitation context

The provided sources do not show CISA KEV listing or confirmed active exploitation. The risk is still material because the attack vector is remote and unauthenticated when a vulnerable server is reachable.

Researcher notes

The bundle identifies CWE-839 and an availability-only CVSS vector. It does not provide exploit proof, packet details, or active exploitation evidence. Validation should focus on version state, reachability, and operational symptoms, not offensive reproduction.

Mitigation direction

  • Upgrade MongoDB 4.2 to 4.2.1 or later.
  • Upgrade MongoDB 4.0 to 4.0.13 or later.
  • Upgrade MongoDB 3.6 to 3.6.15 or later.
  • Upgrade MongoDB 3.4 to 3.4.24 or later.
  • Restrict MongoDB network access to trusted clients only.
  • Check MongoDB guidance for any version-specific operational notes.

Validation and detection

  • Inventory all MongoDB Server versions in production and staging.
  • Confirm no listed version is below its fixed release.
  • Verify MongoDB ports are not exposed to untrusted networks.
  • Review monitoring for unexpected restarts, memory pressure, or availability drops.
  • Confirm upgrade evidence through package, container, or runtime version records.
Prepared
Confidence
high
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-839: 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-2019-20925 mapping review

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

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Vulnerability profileCVE Program record
Severity
High
CVSS
7.5 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/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
0Timeline events
0ADP providers
2Source links

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
7.5CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

7.5High
CVSS 3.1 vector shape for CVE-2019-20925Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/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

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
MongoDB Inc.MongoDB Server4.2, 4.0, 3.6, 3.4unaffected
Weakness

CWE details

CWE-839

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

CWE-839 · source CWE mapping

Numeric Range Comparison Without Minimum Check

Numeric Range Comparison Without Minimum Check represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

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