Versions of the package asyncua before 0.9.96 are vulnerable to Denial of Service (DoS) such that an attacker can send a malformed packet and as a result, the server will enter into an infinite loop and consume excessive memory.

Versions of the package asyncua before 0.9.96 are vulnerable to Improper Authentication such that it is possible to access Address Space without encryption and authentication. **Note:** This issue is a result of missing checks for services that require an active session.

The package node-opcua before 2.74.0 are vulnerable to Denial of Service (DoS) when bypassing the limitations for excessive memory consumption by sending multiple CloseSession requests with the deleteSubscription parameter equal to False.

The package opcua from 0.0.0 are vulnerable to Denial of Service (DoS) via the ExtensionObjects and Variants objects, when it allows unlimited nesting levels, which could result in a stack overflow even if the message size is less than the maximum allowed.

All versions of package opcua; all versions of package asyncua are vulnerable to Denial of Service (DoS) due to a missing limitation on the number of received chunks - per single session or in total for all concurrent sessions. An attacker can exploit this vulnerability by sending an unlimited number of huge chunks (e.g. 2GB each) without sending the Final closing chunk.

The package node-opcua before 2.74.0 are vulnerable to Denial of Service (DoS) by sending a specifically crafted OPC UA message with a special OPC UA NodeID, when the requested memory allocation exceeds the v8’s memory limit.

The package node-opcua before 2.74.0 are vulnerable to Denial of Service (DoS) due to a missing limitation on the number of received chunks - per single session or in total for all concurrent sessions. An attacker can exploit this vulnerability by sending an unlimited number of huge chunks (e.g. 2GB each) without sending the Final closing chunk.

All versions of package freeopcua/freeopcua are vulnerable to Denial of Service (DoS) when bypassing the limitations for excessive memory consumption by sending multiple CloseSession requests with the deleteSubscription parameter equal to False.

The package opcua from 0.0.0 are vulnerable to Denial of Service (DoS) due to a missing limitation on the number of received chunks - per single session or in total for all concurrent sessions. An attacker can exploit this vulnerability by sending an unlimited number of huge chunks (e.g. 2GB each) without sending the Final closing chunk.