Security readout for executives and security teams
Plain-English summary
Applications using vulnerable MongoDB Go Driver versions could marshal attacker-influenced strings into BSON in a way that adds unintended fields. This can undermine data trust or access decisions if those objects are stored or queried. The issue is medium severity and requires a malicious user able to supply crafted object content.
Executive priority
Treat this as a moderate application-layer data integrity risk. It is not evidenced as actively exploited, but vulnerable services that store or trust user-controlled BSON documents should be upgraded and tested on a normal security maintenance timeline.
Technical view
Improper validation of specific cstrings during Go object to BSON marshalling allows potential field injection into marshalled documents. CVSS v3.1 is 6.8: network exploitable, high complexity, low privileges, no user interaction, with high confidentiality and integrity impact and no availability impact.
Likely exposure
Exposure is limited to Go applications that use MongoDB Go Driver versions prior to and including 1.5.0 and marshal attacker-controlled or tenant-controlled string data into BSON documents.
Exploitation context
The provided sources do not show active exploitation, and the CVE is not listed as KEV in the bundle. Exploitation would depend on application-specific data paths where a low-privileged user can influence Go objects before BSON marshalling.
Researcher notes
Focus analysis on BSON marshalling boundaries, especially object fields derived from authenticated users or tenants. The source bundle names field injection as the impact but does not provide exploit details, affected CPEs, or environmental preconditions beyond driver version and crafted string input.
Mitigation direction
- Identify services using the MongoDB Go Driver.
- Upgrade affected driver versions beyond 1.5.0, starting with the referenced 1.5.1 release.
- Prioritize services that marshal user-controlled object fields into BSON.
- Review MongoDB release guidance before rollout.
- Regression test BSON serialization and authorization-sensitive database workflows.
Validation and detection
- Inventory Go module dependencies for MongoDB Go Driver versions.
- Confirm no deployed service runs version 1.5.0 or earlier.
- Review code paths that marshal external input into BSON documents.
- Test that suspicious string fields cannot create unintended BSON fields.
- Check logs for anomalous document fields where user input is stored.
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-1287: 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-2021-20329 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
- 6.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/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:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N1.65.2Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.8MediumVector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/mongodb/mongo-go-driver/releases/tag/v1.5.1CVE 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 Validation of Specified Type of Input
Improper Validation of Specified Type of Input represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.