A vulnerability, which was classified as critical, was found in hughsk flat up to 5.0.0. This affects the function unflatten of the file index.js. The manipulation leads to improperly controlled modification of object prototype attributes (prototype pollution). It is possible to initiate the attack remotely. Upgrading to version 5.0.1 is able to address this issue. The name of the patch is 20ef0ef55dfa028caddaedbcb33efbdb04d18e13. It is recommended to upgrade the affected component. The identifier VDB-216777 was assigned to this vulnerability.
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 |
|---|---|---|---|
| Flat | Flat_project | * | 5.0.1 (excluding) |
| Chromium-browser | Ubuntu | bionic | * |
| Chromium-browser | Ubuntu | trusty | * |
| Chromium-browser | Ubuntu | upstream | * |
| Chromium-browser | Ubuntu | xenial | * |
| Qt6-webengine | Ubuntu | kinetic | * |
| Qt6-webengine | Ubuntu | lunar | * |
| Qt6-webengine | Ubuntu | mantic | * |
| Qt6-webengine | Ubuntu | trusty | * |
| Qt6-webengine | Ubuntu | xenial | * |
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.