matrix-js-sdk is a Matrix messaging protocol Client-Server SDK for JavaScript. In versions prior to 19.4.0 events sent with special strings in key places can temporarily disrupt or impede the matrix-js-sdk from functioning properly, potentially impacting the consumers ability to process data safely. Note that the matrix-js-sdk can appear to be operating normally but be excluding or corrupting runtime data presented to the consumer. This issue has been fixed in matrix-js-sdk 19.4.0 and users are advised to upgrade. Users unable to upgrade may mitigate this issue by redacting applicable events, waiting for the sync processor to store data, and restarting the client. Alternatively, redacting the applicable events and clearing all storage will often fix most perceived issues. In some cases, no workarounds are possible.
The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Javascript_sdk | Matrix | * | 19.4.0 (excluding) |
By adding or modifying attributes of an object prototype, it is possible to create attributes that exist on every object, or replace critical attributes with malicious ones. This can be problematic if the product depends on existence or non-existence of certain attributes, or uses pre-defined attributes of object prototype (such as hasOwnProperty, toString or valueOf). This weakness is usually exploited by using a special attribute of objects called proto, constructor or prototype. Such attributes give access to the object prototype. This weakness is often found in code that assigns object attributes based on user input, or merges or clones objects recursively.