CVE-2021-20330: medium-severity vulnerability in MongoDB Server
Specific replication command with malformed oplog entries can crash secondaries
Published · Updated
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13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 6.5epss 1.1%
An attacker with basic CRUD permissions on a replicated collection can run the applyOps command with specially malformed oplog entries, resulting in a potential denial of service on secondaries. This issue affects MongoDB Server v4.0 versions prior to 4.0.27; MongoDB Server v4.2 versions prior to 4.2.16; MongoDB Server v4.4 versions prior to 4.4.9.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Affected products
MongoDB Inc. · MongoDB ServerRelated CVEs — MongoDB Server
In the same product, most dangerous first.
CVE-2025-14847HIGHZlib compressed protocol header length confusion may allow memory readEPSS 83.2%KEVCVE-2021-32040MEDIUMLarge aggregation pipelines with a specific stage can crash mongod under default configurationEPSS 2.0%CVE-2020-7925HIGHDenial of Service when processing malformed Role namesEPSS 1.7%CVE-2019-20925HIGHDenial of service via malformed network packetEPSS 1.7%CVE-2018-20802MEDIUMPost-auth queries on compound index may crash mongodEPSS 1.6%CVE-2020-7928MEDIUMImproper neutralization of null byte leads to read overrunEPSS 1.4%