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Fencer Vulns
medium 5.3

CVE-2021-20333 json

Server log entry spoofing via newline injection

published 2021-07-23 5 y ago modified 2026-09-08 2 mo ago also BIT-mongodb-2021-20333 , EUVD-2021-7751

cvss
5.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.3%
EPSS 1.3% chance of exploitation in 30 days, percentile 70%
public exploits
0
none known

Summary

Sending specially crafted commands to a MongoDB Server may result in artificial log entries being generated or for log entries to be split. This issue affects MongoDB Server v3.6 versions prior to 3.6.20; MongoDB Server v4.0 versions prior to 4.0.21 and MongoDB Server v4.2 versions prior to 4.2.10.

Patch / fix

  • bitnami mongodb 3.6.20, 4.0.21, 4.2.10
  • MongoDB Inc. MongoDB Server 3.6.20, 4.0.21, 4.2.10

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

cisa ICSA-26-218-01 updated cvss 5.3

ABB Ability Zenon

  • ABB Ability Zenon /all IIoT services with MongoDB 4.2
    affected: mitigation

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

red hat product security vex CVE-2021-20333 updated cvss 5.3

mongodb: server log entry spoofing via newline injection

  • Red Hat OpenStack Platform 10 (Newton) mongodb, mongodb-server Red Hat Software Collections rh-mongodb36-mongodb, rh-mongodb36-mongodb-test, rh-mongodb36-mongodb-server, rh-mongodb36-mongodb-syspaths, rh-mongodb36-mongodb-server-syspaths
    affected: no fix planned “Out of support scope”
  • Red Hat Update Infrastructure 3 for Cloud Providers mongodb
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.30% chance of exploitation in the next 30 days, higher than 70% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • jira.mongodb.org https://jira.mongodb.org/browse/SERVER-50605 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
NVD 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:P/A:N
OSV 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Affected packages

ecosystem package affected fixed in
bitnami mongodb
>=3.6.0, <3.6.20
>=4.0.0, <4.0.21
>=4.2.0, <4.2.10
3.6.20
4.0.21
4.2.10

Affected products

  • MongoDB Inc. MongoDB Server

Classification

Weakness
  • CWE-117 Improper Output Neutralization for Logs
  • CWE-116 Improper Encoding or Escaping of Output
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.