If the MongoDB Server running on Windows or macOS is configured to use TLS with a specific set of configuration options that are already known to work securely in other platforms (e.g. Linux), it is possible that client certificate validation may not be in effect, potentially allowing client to establish a TLS connection with the server that supplies any certificate. This issue affect all MongoDB Server v6.3 versions, MongoDB Server v5.0 versions v5.0.0 to v5.0.14 and all MongoDB Server v4.4 versions.

It may be possible to have an extremely long aggregation pipeline in conjunction with a specific stage/operator and cause a stack overflow due to the size of the stack frames used by that stage. If an attacker could cause such an aggregation to occur, they could maliciously crash MongoDB in a DoS attack. This vulnerability affects MongoDB Server v4.4 versions prior to and including 4.4.28, MongoDB Server v5.0 versions prior to 5.0.4 and MongoDB Server v4.2 versions prior to 4.2.16. Workaround: >= v4.2.16 users and all v4.4 users can add the --setParameter internalPipelineLengthLimit=50 instead of the default 1000 to mongod at startup to prevent a crash.

An authenticated user without any specific authorizations may be able to repeatedly invoke the features command where at a high volume may lead to resource depletion or generate high lock contention. This may result in denial of service and in rare cases could result in id field collisions. This issue affects MongoDB Server v5.0 versions prior to and including 5.0.3; MongoDB Server v4.4 versions prior to and including 4.4.9; MongoDB Server v4.2 versions prior to and including 4.2.16 and MongoDB Server v4.0 versions prior to and including 4.0.28

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.

A user authorized to performing a specific type of find query may trigger a denial of service. This issue affects MongoDB Server v4.4 versions prior to 4.4.4.

A user authorized to perform database queries may trigger a read overrun and access arbitrary memory by issuing specially crafted queries. This issue affects MongoDB Server v4.4 versions prior to 4.4.1; MongoDB Server v4.2 versions prior to 4.2.9; MongoDB Server v4.0 versions prior to 4.0.20 and MongoDB Server v3.6 versions prior to 3.6.20.

A user authorized to perform database queries may trigger denial of service by issuing specially crafted queries, which use the $mod operator to overflow negative values. This issue affects: MongoDB Inc. MongoDB Server v4.4 versions prior to 4.4.1; v4.2 versions prior to 4.2.9; v4.0 versions prior to 4.0.20; v3.6 versions prior to 3.6.20.

A user authorized to perform database queries may cause denial of service by issuing a specially crafted query which violates an invariant in the server selection subsystem. This issue affects MongoDB Server v4.4 versions prior to 4.4.1. Versions before 4.4 are not affected.

MongoDB on Red Hat Satellite 6 allows local users to bypass authentication by logging in with an empty password and delete information which can cause a Denial of Service.