CVE-2021-20331

Authentication-data disclosure via case-mismatched command redaction

Published May 13, 2021 · Updated Sep 16, 2024

Information exposure in MongoDB C# Driver 2.12 through 2.12.1 allows local users to disclose authentication data via command events. CommandEventHelper lowercases command names but compares several against mixed-case labels, so sensitive commands and replies escape redaction. Exposure requires a non-default command listener and an application path that reveals the event data, such as persistent logging; the consequence is limited to confidentiality.

CVSS severity4.2
Medium
EPSS probability0.62%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information exposure in MongoDB C# Driver 2.12 through 2.12.1 allows local users to disclose authentication data via command events. CommandEventHelper lowercases command names but compares several against mixed-case labels, so sensitive commands and replies escape redaction. Exposure requires a non-default command listener and an application path that reveals the event data, such as persistent logging; the consequence is limited to confidentiality.

The record

CVE
CVE-2021-20331
Published
May 13, 2021
Updated
Sep 16, 2024
Vendor
MongoDB
Product
MongoDB .NET/C# Driver
Classifications
CWE-200
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. May 13, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2.12 <=2.12.1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

MongoDB · MongoDB .NET/C# Driverversion=2.12 <=2.12.1
MongoDB · MongoDB C++ Driverversion=2.12 <=2.12.1

Published CVSS scores

4.2MongoDB, Inc.CVSS:3.1/AV:L/AC:L/PR:H/UI:R/S:U/C:H/I:N/A:N
3.5NIST NVDAV:N/AC:M/Au:S/C:P/I:N/A:N
4.9NIST NVDCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-200Exposure of Sensitive Information to an Unauthorized Actor

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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