95 lines
3.7 KiB
Markdown
95 lines
3.7 KiB
Markdown
|
# Threat analysis for the federated star activity
|
|||
|
|
|
|||
|
|
## Technical Background
|
|||
|
|
### Control Flow
|
|||
|
|
|
|||
|
|
```mermaid
|
|||
|
|
sequenceDiagram
|
|||
|
|
participant fs as foreign_repository_server
|
|||
|
|
participant os as our_repository_server
|
|||
|
|
|
|||
|
|
fs ->> os: post /api/activitypub/repository-id/1/inbox {Start-Activity}
|
|||
|
|
activate os
|
|||
|
|
os ->> os: validate request inputs
|
|||
|
|
activate repository
|
|||
|
|
os ->> repository: validate
|
|||
|
|
repository ->> repository: search for reop with object-id
|
|||
|
|
deactivate repository
|
|||
|
|
activate person
|
|||
|
|
os ->> person: validate
|
|||
|
|
person ->> person: search for ser with actor-id
|
|||
|
|
person ->> fs: get /api/activitypub/user-id/{id from actor}
|
|||
|
|
person ->> person: create user from response
|
|||
|
|
deactivate person
|
|||
|
|
os ->> repository: execute star action
|
|||
|
|
os -->> fs: 200 ok
|
|||
|
|
deactivate os
|
|||
|
|
```
|
|||
|
|
|
|||
|
|
### Data transfered
|
|||
|
|
|
|||
|
|
```
|
|||
|
|
# edn notation
|
|||
|
|
{@context [
|
|||
|
|
"as": "https://www.w3.org/ns/activitystreams#",
|
|||
|
|
"forge": "https://forgefed.org/ns#",],
|
|||
|
|
::as/id "https://repo.prod.meissa.de/api/v1/activitypub/user-id/1/outbox/12345",
|
|||
|
|
::as/type "Star",
|
|||
|
|
::forge/source "forgejo",
|
|||
|
|
::as/actor "https://repo.prod.meissa.de/api/v1/activitypub/user-id/1",
|
|||
|
|
::as/object "https://codeberg.org/api/v1/activitypub/repository-id/12"
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
# json notation
|
|||
|
|
{"id": "https://repo.prod.meissa.de/api/v1/activitypub/user-id/1/outbox/12345",
|
|||
|
|
"type": "Star",
|
|||
|
|
"source": "forgejo",
|
|||
|
|
"actor": "https://repo.prod.meissa.de/api/v1/activitypub/user-id/1",
|
|||
|
|
"object": "https://codeberg.org/api/v1/activitypub/repository-id/1"
|
|||
|
|
}
|
|||
|
|
```
|
|||
|
|
|
|||
|
|
### Data Flow
|
|||
|
|
|
|||
|
|
```mermaid
|
|||
|
|
flowchart TD
|
|||
|
|
A(User) --> |stars a federated repository| B(foreign repository server)
|
|||
|
|
B --> |Star Activity| C(our repository server)
|
|||
|
|
C --> |get repository localy| D(our repos database)
|
|||
|
|
C --> |get Person Actor| B
|
|||
|
|
C --> |create federated user localy| D
|
|||
|
|
C --> |add star to repo localy| D
|
|||
|
|
```
|
|||
|
|
|
|||
|
|
## Analysis
|
|||
|
|
### Assets
|
|||
|
|
|
|||
|
|
1. **Service Availability**: The availability of our or foreign servers.
|
|||
|
|
2. **Reputation**: Our standing against freinds and others.
|
|||
|
|
|
|||
|
|
### Actors
|
|||
|
|
|
|||
|
|
1. **Script Kiddies**: Boored teens, willing to do some illigal without deep knowlege of tech details but broad knowlege across internet discussions. Able to do some bash / python scripting.
|
|||
|
|
|
|||
|
|
### Threat
|
|||
|
|
|
|||
|
|
1. Script Kiddi sends a Star Activity containing an attack target url `http://attacked.target/very/special/path` in place of actor. Our repository server sends an `get Person Actor` request to this url. The attacked target gets DenialdOffServices. We loose CPU & reputation.
|
|||
|
|
|
|||
|
|
### DREAD-Score
|
|||
|
|
|
|||
|
|
| Threat | Damage | Reproducibility | Exploitability | Affected Users | Discoverability | Mitigations |
|
|||
|
|
| :----- | :------ | :-------------- | :------------- | :------------- | :-------------- | :---------- |
|
|||
|
|
| 1. | ... tbd | | | | | |
|
|||
|
|
| 2. | ... tbd | | | | | |
|
|||
|
|
|
|||
|
|
Bewertet wird mit Schulnoten von 1 - 6
|
|||
|
|
|
|||
|
|
* Damage – wie groß wäre der Schaden, wenn der Angriff erfolgreich ist? 6 ist ein sehr schlimmer Schaden.
|
|||
|
|
* Reproducibility – wie einfach wäre der Angriff reproduzierbar? 6 ist sehr einfach zu reproduzieren.
|
|||
|
|
* Exploitability – wieviel Zeit, Aufwand und Erfahrung sind notwendig, um die Bedrohung auszunutzen? 6 ist sehr einfach zu machen.
|
|||
|
|
* Affected Users – wenn eine Bedrohung ausgenutzt werden würde, wieviel Prozent der Benutzer wären betroffen?
|
|||
|
|
* Discoverability – Wie einfach lässt sich ein Angriff entdecken? Muss der Angreifer Strafverfolgung erwarten? 6 ist sehr schwer zu entdecken / ist gar nicht illegal
|
|||
|
|
|
|||
|
|
## Reference
|
|||
|
|
|
|||
|
|
* https://geballte-sicherheit.de/threat-modelling-bedrohungsanalyse-7-teil-einstufung-von-bedrohungen-ranking-of-threats/
|