Security readout for executives and security teams
Plain-English summary
A short-lived MongoDB Node.js encryption library version could fail to properly validate a KMS server certificate. In a privileged network interception scenario, encrypted field protection could be undermined for applications using CSFLE. Workloads not using Field Level Encryption are not affected.
Executive priority
Treat as targeted but important. It can undermine sensitive-field encryption, but only for a specific deprecated package version and MITM-capable network position. Prioritize inventory and replacement over emergency response unless exposed systems are found.
Technical view
CVE-2021-20327 affects mongodb-client-encryption 1.2.0. The issue is CWE-295 certificate validation failure against KMS connections. With active MITM access in a privileged network position, KMS traffic could be intercepted, making client-side field level encryption ineffective. Sources state no impact for non-FLE workloads.
Likely exposure
Exposure is narrow: MongoDB Node.js applications using mongodb-client-encryption exactly version 1.2.0 and CSFLE, especially outside the stated AWS, GCP, or Azure network-fabric compensating controls.
Exploitation context
The bundle does not show known active exploitation or KEV listing. Exploitation requires a privileged active MITM position and applies only where the vulnerable CSFLE KMS certificate validation path is present.
Researcher notes
Evidence identifies internal discovery, medium CVSS 6.4, CWE-295, and exact affected version 1.2.0. The bundle names deprecation but does not provide exploit evidence or a specific fixed replacement version.
Mitigation direction
- Identify and remove mongodb-client-encryption version 1.2.0 from Node.js applications.
- Check MongoDB guidance and NODE-3125 for supported remediation direction.
- Confirm CSFLE KMS traffic uses trusted network paths and provider compensating controls where applicable.
- Prioritize applications using CSFLE outside AWS, GCP, or Azure network fabrics.
Validation and detection
- Inventory package manifests and lockfiles for mongodb-client-encryption 1.2.0.
- Confirm whether each application actually uses Client-Side Field Level Encryption.
- Map CSFLE KMS provider and runtime environment for each affected application.
- Review network architecture for possible privileged interception points between application and KMS.
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-295: 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 lookupCVE-2021-20327 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
- Medium
- CVSS
- 6.4 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
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 vector scores
1 official scoreWe 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.
CVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N1.25.2Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.4MediumVector: CVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://jira.mongodb.org/browse/NODE-3125CVE reference · x_refsource_MISC
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 Certificate Validation
Improper Certificate Validation represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.