CVE-2021-20328
MongoDB Java driver client-side field level encryption not verifying KMS host name
Specific versions of the Java driver that support client-side field level encryption (CSFLE) fail to perform correct host name verification on the KMS server’s certificate. This vulnerability in combination with a privileged network position active MITM attack could result in interception of traffic between the Java driver and the KMS service rendering Field Level Encryption ineffective. This issue was discovered during internal testing and affects all versions of the Java driver that support CSFLE. The Java async, Scala, and reactive streams drivers are not impacted. This vulnerability does not impact driver traffic payloads with CSFLE-supported key services originating from applications residing inside the AWS, GCP, and Azure network fabrics due to compensating controls in these environments. This issue does not impact driver workloads that don’t use Field Level Encryption.
Attack profile
How easy it is to exploit
- Attack vector
- Adjacent network
- Complexity
- High
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
6.4
MongoDB Java driver client-side field level encryption not verifying KMS host name
Specific versions of the Java driver that support client-side field level encryption (CSFLE) fail to perform correct host name verification on the KMS server’s certificate. This vulnerability in combination with a privileged network position active MITM attack could result in interception of traffic between the Java driver and the KMS service rendering Field Level Encryption ineffective. This issue was discovered during internal testing and affects all versions of the Java driver that support CSFLE. The Java async, Scala, and reactive streams drivers are not impacted. This vulnerability does not impact driver traffic payloads with CSFLE-supported key services originating from applications residing inside the AWS, GCP, and Azure network fabrics due to compensating controls in these environments. This issue does not impact driver workloads that don’t use Field Level Encryption.
- Record
CVE-2021-20328- CVSS 3.1
- 6.4 Medium
CVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N - Weakness
- CWE-295
- Updated
- 2026-11-02
EUVDEUVD-2022-5169
6.4
Specific versions of the Java driver that support client-side field level encryption (CSFLE) fail to perform correct host name verification on the KMS server’s certificate. This vulnerability in combination with a privileged network position active MITM attack could result in interception of traffic between the Java driver and the KMS service rendering Field Level Encryption ineffective. This issue was discovered during internal testing and affects all versions of the Java driver that support CSFLE. The Java async, Scala, and reactive streams drivers are not impacted. This vulnerability does not impact driver traffic payloads with CSFLE-supported key services originating from applications residing inside the AWS, GCP, and Azure network fabrics due to compensating controls in these environments. This issue does not impact driver workloads that don’t use Field Level Encryption.
- Record
EUVD-2022-5169- CVSS 3.1
- 6.4 Medium
CVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-rghw-6px2-fgwc
6.8
Improper Certificate Validation in MongoDB
Specific versions of the Java driver that support client-side field level encryption (CSFLE) fail to perform correct host name verification on the KMS server’s certificate. This vulnerability in combination with a privileged network position active MITM attack could result in interception of traffic between the Java driver and the KMS service rendering Field Level Encryption ineffective. This issue was discovered during internal testing and affects all versions of the Java driver that support CSFLE. The Java async, Scala, and reactive streams drivers are not impacted. This vulnerability does not impact driver traffic payloads with CSFLE-supported key services originating from applications residing inside the AWS, GCP, and Azure network fabrics due to compensating controls in these environments. This issue does not impact driver workloads that don’t use Field Level Encryption.
- Record
GHSA-rghw-6px2-fgwc- CVSS 3.1
- 6.8 Medium
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-295
- Updated
- 2026-11-02
NVD
6.4
Specific versions of the Java driver that support client-side field level encryption (CSFLE) fail to perform correct host name verification on the KMS server’s certificate. This vulnerability in combination with a privileged network position active MITM attack could result in interception of traffic between the Java driver and the KMS service rendering Field Level Encryption ineffective. This issue was discovered during internal testing and affects all versions of the Java driver that support CSFLE. The Java async, Scala, and reactive streams drivers are not impacted. This vulnerability does not impact driver traffic payloads with CSFLE-supported key services originating from applications residing inside the AWS, GCP, and Azure network fabrics due to compensating controls in these environments. This issue does not impact driver workloads that don’t use Field Level Encryption.
- Record
CVE-2021-20328- CVSS 3.1
- 6.4 Medium
CVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N - CVSS 3.1
- 6.8 Medium
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N - CVSS 2.0
- 4.3 Medium
AV:A/AC:M/Au:N/C:P/I:P/A:N - Weakness
- CWE-295
- Updated
- 2026-11-02
OSV
6.8
Specific versions of the Java driver that support client-side field level encryption (CSFLE) fail to perform correct host name verification on the KMS server’s certificate. This vulnerability in combination with a privileged network position active MITM attack could result in interception of traffic between the Java driver and the KMS service rendering Field Level Encryption ineffective. This issue was discovered during internal testing and affects all versions of the Java driver that support CSFLE. The Java async, Scala, and reactive streams drivers are not impacted. This vulnerability does not impact driver traffic payloads with CSFLE-supported key services originating from applications residing inside the AWS, GCP, and Azure network fabrics due to compensating controls in these environments. This issue does not impact driver workloads that don’t use Field Level Encryption.
- Record
CVE-2021-20328- CVSS 3.1
- 6.8 Medium
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N - Updated
- 2026-11-02
OSVGHSA-rghw-6px2-fgwc
6.8
Improper Certificate Validation in MongoDB
Specific versions of the Java driver that support client-side field level encryption (CSFLE) fail to perform correct host name verification on the KMS server’s certificate. This vulnerability in combination with a privileged network position active MITM attack could result in interception of traffic between the Java driver and the KMS service rendering Field Level Encryption ineffective. This issue was discovered during internal testing and affects all versions of the Java driver that support CSFLE. The Java async, Scala, and reactive streams drivers are not impacted. This vulnerability does not impact driver traffic payloads with CSFLE-supported key services originating from applications residing inside the AWS, GCP, and Azure network fabrics due to compensating controls in these environments. This issue does not impact driver workloads that don’t use Field Level Encryption.
- Record
GHSA-rghw-6px2-fgwc- CVSS 3.1
- 6.8 Medium
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-295
- Updated
- 2026-11-02
OSVUBUNTU-CVE-2021-20328
6.4
Specific versions of the Java driver that support client-side field level encryption (CSFLE) fail to perform correct host name verification on the KMS server’s certificate. This vulnerability in combination with a privileged network position active MITM attack could result in interception of traffic between the Java driver and the KMS service rendering Field Level Encryption ineffective. This issue was discovered during internal testing and affects all versions of the Java driver that support CSFLE. The Java async, Scala, and reactive streams drivers are not impacted. This vulnerability does not impact driver traffic payloads with CSFLE-supported key services originating from applications residing inside the AWS, GCP, and Azure network fabrics due to compensating controls in these environments. This issue does not impact driver workloads that don’t use Field Level Encryption.
- Record
UBUNTU-CVE-2021-20328- CVSS 3.1
- 6.4 Medium
CVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N - CVSS 3.1
- 6.8 Medium
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
org.mongodb:mongodb-driverMaven |
3.11.0 to 3.11.2 | 3.11.3 |
org.mongodb:mongodb-driverMaven |
3.12.0 to 3.12.7 | 3.12.8 |
org.mongodb:mongodb-driver-syncMaven |
4.0.0 to 4.0.5 | 4.0.6 |
org.mongodb:mongodb-driver-syncMaven |
4.1.0 to 4.1.1 | 4.1.2 |
org.mongodb:mongodb-driver-syncMaven |
4.2.0 to 4.2.0 | 4.2.1 |
org.mongodb:mongo-java-driverMaven |
3.11.0 to 3.11.2 | 3.11.3 |
org.mongodb:mongo-java-driverMaven |
3.12.0 to 3.12.7 | 3.12.8 |
org.mongodb:mongodb-driver-legacyMaven |
4.0.0 to 4.0.5 | 4.0.6 |
org.mongodb:mongodb-driver-legacyMaven |
4.1.0 to 4.1.1 | 4.1.2 |
org.mongodb:mongodb-driver-legacyMaven |
3.11.0 to 3.11.2 | 3.11.3 |
Show 26 moreShow less
| Package | Affected | Fixed |
|---|---|---|
org.mongodb:mongodb-driver-legacyMaven |
3.12.0 to 3.12.7 | 3.12.8 |
org.mongodb:mongodb-driver-syncMaven |
3.12.0 to 3.12.7 | 3.12.8 |
org.mongodb:mongodb-driver-syncMaven |
3.11.0 to 3.11.2 | 3.11.3 |
org.mongodb:mongodb-driver-legacyMaven |
4.2.0 to 4.2.0 | 4.2.1 |
org.mongodb:mongodb-driverMaven |
3.11.0 up to 3.11.3, plus listed versions 3.11.13.11.2 |
3.11.3 |
org.mongodb:mongodb-driverMaven |
3.12.0 up to 3.12.8, plus listed versions 3.12.13.12.23.12.33.12.43.12.53.12.63.12.7 |
3.12.8 |
org.mongodb:mongodb-driver-syncMaven |
4.0.0 up to 4.0.6, plus listed versions 4.0.14.0.24.0.34.0.44.0.5 |
4.0.6 |
org.mongodb:mongodb-driver-syncMaven |
4.1.0 up to 4.1.2, plus listed versions 4.1.1 |
4.1.2 |
org.mongodb:mongodb-driver-syncMaven |
4.2.0 up to 4.2.1 | 4.2.1 |
org.mongodb:mongo-java-driverMaven |
3.11.0 up to 3.11.3, plus listed versions 3.11.13.11.2 |
3.11.3 |
org.mongodb:mongo-java-driverMaven |
3.12.0 up to 3.12.8, plus listed versions 3.12.13.12.23.12.33.12.43.12.53.12.63.12.7 |
3.12.8 |
org.mongodb:mongodb-driver-legacyMaven |
4.0.0 up to 4.0.6, plus listed versions 4.0.14.0.24.0.34.0.44.0.5 |
4.0.6 |
org.mongodb:mongodb-driver-legacyMaven |
4.1.0 up to 4.1.2, plus listed versions 4.1.1 |
4.1.2 |
org.mongodb:mongodb-driver-legacyMaven |
3.11.0 up to 3.11.3, plus listed versions 3.11.13.11.2 |
3.11.3 |
org.mongodb:mongodb-driver-legacyMaven |
3.12.0 up to 3.12.8, plus listed versions 3.12.13.12.23.12.33.12.43.12.53.12.63.12.7 |
3.12.8 |
org.mongodb:mongodb-driver-syncMaven |
3.12.0 up to 3.12.8, plus listed versions 3.12.13.12.23.12.33.12.43.12.53.12.63.12.7 |
3.12.8 |
org.mongodb:mongodb-driver-syncMaven |
3.11.0 up to 3.11.3, plus listed versions 3.11.13.11.2 |
3.11.3 |
org.mongodb:mongodb-driver-legacyMaven |
4.2.0 up to 4.2.1 | 4.2.1 |
mongo-java-driverUbuntu:16.04:LTS |
All versions, plus listed versions 2.12.4-1 |
None known |
mongo-java-driverUbuntu:18.04:LTS |
All versions, plus listed versions 3.3.0-13.6.2-13.6.3-2~18.04 |
None known |
mongo-java-driverUbuntu:20.04:LTS |
All versions, plus listed versions 3.6.3-2 |
None known |
mongo-java-driverUbuntu:22.04:LTS |
All versions, plus listed versions 3.6.3-2 |
None known |
mongo-java-driverUbuntu:24.04:LTS |
All versions, plus listed versions 3.6.3-2 |
None known |
mongo-java-driverUbuntu:25.10 |
All versions, plus listed versions 3.6.3-2 |
None known |
mongo-java-driverUbuntu:26.10 |
All versions, plus listed versions 3.6.3-2.1 |
None known |
mongo-java-driverUbuntu:26.04:LTS |
All versions, plus listed versions 3.6.3-23.6.3-2build13.6.3-2.1 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-20328 is a medium vulnerability (CVSS 6.4) in Mongodb Java Driver, published February 25, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.44%, the 37th percentile. Fixed in org.mongodb:mongodb-driver 3.11.3.