title: Specific replication command with malformed oplog entries can crash secondaries
description: 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.
problem types: CWE-20 Improper Input Validation
affected:
{
defaultStatus: unaffected
product: MongoDB Server
vendor: MongoDB Inc.
versions:
lessThan: 4.0.27, status: affected, version: 4.0, versionType: custom
lessThan: 4.2.16, status: affected, version: 4.2, versionType: custom
lessThan: 4.4.9, status: affected, version: 4.4, versionType: custom
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: HIGH
baseScore: 6.5
baseSeverity: MEDIUM
confidentialityImpact: NONE
integrityImpact: NONE
privilegesRequired: LOW
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
version: 3.1
]
format: CVSS
scenarios: GENERAL