Package Instance

Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
matrix-react-sdk is a react-based SDK for inserting a Matrix chat/VoIP client into a web page. Prior to version 3.71.0, plain text messages containing HTML tags are rendered as HTML in the search results. To exploit this, an attacker needs to trick a user into searching for a specific message containing an HTML injection payload. No cross-site scripting attack is possible due to the hardcoded content security policy. Version 3.71.0 of the SDK patches over the issue. As a workaround, restarting the client will clear the HTML injection.

Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
matrix-react-sdk is a Matrix chat protocol SDK for React Javascript. In certain configurations, data sent by remote servers containing special strings in key locations could cause modifications of the `Object.prototype`, disrupting matrix-react-sdk functionality, causing denial of service and potentially affecting program logic. This is fixed in matrix-react-sdk 3.69.0 and users are advised to upgrade. There are no known workarounds for this vulnerability. Note this advisory is distinct from GHSA-2x9c-qwgf-94xr which refers to a similar issue.

User content sandbox can be confused into opening arbitrary documents
### Impact

The user content sandbox can be abused to trick users into opening unexpected documents after several user interactions. The content can be opened with a `blob` origin from the Matrix client, so it is possible for a malicious document to access user messages and secrets.

### Patches

This has been fixed by https://github.com/matrix-org/matrix-react-sdk/pull/5657, which is included in 3.15.0.

### Workarounds

There are no known workarounds.

Matrix SDK for React's URL preview setting for a room is controllable by the homeserver
### Impact
A malicious homeserver could manipulate a user's account data to cause the client to enable URL previews in end-to-end encrypted rooms, in which case any URLs in encrypted messages would be sent to the server.

Even if the CVSS score would be 4.1 ([AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:N/A:N](https://nvd.nist.gov/vuln-metrics/cvss/v3-calculator?vector=AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:N/A:N&version=3.1)) the maintainer classifies this as High severity issue.

### Patches
This was patched in matrix-react-sdk 3.105.1.

### Workarounds
Deployments that trust their homeservers, as well as closed federations of trusted servers, are not affected.

### References
N/A.

Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
matrix-react-sdk is a Matrix chat protocol SDK for React Javascript. Events sent with special strings in key places can temporarily disrupt or impede the matrix-react-sdk from functioning properly, such as by causing room or event tile crashes. The remainder of the application can appear functional, though certain rooms/events will not be rendered. This issue has been fixed in matrix-react-sdk 3.53.0 and users are advised to upgrade. There are no known workarounds for this vulnerability.