The on_get_missing_events function in handlers/federation.py in Matrix Synapse before 0.31.1 has a security bug in the get_missing_events federation API where event visibility rules were not applied correctly.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Synapse | Matrix | * | 0.31.1 (excluding) |
| Matrix-synapse | Ubuntu | artful | * |
| Matrix-synapse | Ubuntu | bionic | * |
| Matrix-synapse | Ubuntu | cosmic | * |
| Matrix-synapse | Ubuntu | disco | * |
| Matrix-synapse | Ubuntu | eoan | * |
| Matrix-synapse | Ubuntu | esm-apps/bionic | * |
| Matrix-synapse | Ubuntu | groovy | * |
| Matrix-synapse | Ubuntu | hirsute | * |
| Matrix-synapse | Ubuntu | impish | * |
| Matrix-synapse | Ubuntu | mantic | * |
| Matrix-synapse | Ubuntu | upstream | * |