mirror of
https://github.com/stulle123/kakaotalk_analysis.git
synced 2025-03-12 08:55:55 +00:00
Finish RECON.md
This commit is contained in:
stulle123
parent
ec2190cd92
commit
bd98dc832d
180
RECON.md
180
RECON.md
|
|
@ -1,14 +1,6 @@
|
|||
# Recon
|
||||
|
||||
- [Related Work](#related-work)
|
||||
- [Possible Vectors](#possible-attack-vectors)
|
||||
- [Registration and Login](#registration-and-login)
|
||||
- [Cloud](#cloud)
|
||||
- [LOCO Protocol Attacks](#loco-protocol-attacks)
|
||||
- [Message Parsing](#message-parsing-zero-click)
|
||||
- [Malicious App](#malicious-third-party-app)
|
||||
- [Operator-side Attacks](#operator-side-attacks)
|
||||
- [General Infos](#general-infos)
|
||||
- [General Infos](#general-app-infos)
|
||||
- [Files](#files)
|
||||
- [Rest APIs](#rest-apis)
|
||||
- [Activities](#activities)
|
||||
|
|
@ -17,88 +9,16 @@
|
|||
- [Broadcast Receivers](#broadcast-receivers)
|
||||
- [WebViews](#webviews)
|
||||
- [Firebase](#firebase)
|
||||
- [Intents](#intents)
|
||||
- [Native Libs](#native-libs)
|
||||
- [Open-Source Libs](#open-source-libs)
|
||||
- [Crypto](#crypto)
|
||||
- [Secret Chat](#secret-chat)
|
||||
- [Appendix](#appendix)
|
||||
- [Related Work](#related-work)
|
||||
- [Possible Vectors](#attack-vector-brainstorming)
|
||||
|
||||
## Related Work
|
||||
> Disclaimer: Initial recon was performed on an older version of KakaoTalk (`10.1.7`).
|
||||
|
||||
How things work:
|
||||
|
||||
- [Kakaotalk Messaging Architecture](https://kth.diva-portal.org/smash/get/diva2:1046438/FULLTEXT01.pdf#page=75)
|
||||
- [User Registration and Login](https://kth.diva-portal.org/smash/get/diva2:1046438/FULLTEXT01.pdf#page=79)
|
||||
- [LOCO protocol](https://kth.diva-portal.org/smash/get/diva2:1046438/FULLTEXT01.pdf#page=77)
|
||||
|
||||
Flaws:
|
||||
|
||||
- [Protocol flaws](https://kth.diva-portal.org/smash/get/diva2:1046438/FULLTEXT01.pdf#page=100)
|
||||
- [App security flaws](https://kth.diva-portal.org/smash/get/diva2:1046438/FULLTEXT01.pdf#page=105)
|
||||
|
||||
## Possible Attack Vectors
|
||||
|
||||
### Registration and Login
|
||||
|
||||
- Register an attacker's device to the victim's KakaoTalk account
|
||||
- Get victims account credentials email/pw (e.g., via a data dump on breached.vc)
|
||||
- Brute-force 4-digit pin
|
||||
- Intercept SMS during registration to get the pincode (e.g., via SS7 access)
|
||||
- Register an attacker's device via flaws in the LOCO protocol (`CHECKIN` and `LOGINLIST` commands?)
|
||||
- Check out insecure REST API endpoints for authorization flaws
|
||||
- Code injection into insecure REST API endpoints
|
||||
- QR Code login (`xm.a` and `vm.q` Java classes)
|
||||
- `/talk/account/qrCodeLogin/info.json?id=eyJwcm90b2NvbCI6InYxIiwiY2hhbGxlbmdlIjoiNlB6MFMzdkRQMmlFUTZoRXh5YW5mWGtOelNHU0RRIn0=`
|
||||
- `{"protocol":"v1","challenge":"6Pz0S3vDP2iEQ6hExyanfXkNzSGSDQ"}`
|
||||
- `m.w.R1` method computes a MAC of the challenge
|
||||
- The OAuth Refresh Token seems to be the MAC key
|
||||
- How to obtain them? How are they generated? How long do they live?
|
||||
- `ym.a` class builds the POST request
|
||||
- API endpoints in interface `e31.j`
|
||||
- Test PW Reset Functionality
|
||||
|
||||
### Cloud
|
||||
|
||||
- Cloud back-up (weak password)
|
||||
- Secret Chat messages won’t be stored
|
||||
- Tamper with plaintext asset downloads via HTTP (parser attacks on the client possible?)
|
||||
|
||||
### LOCO Protocol Attacks
|
||||
|
||||
- Spoof victim (`CHECKIN` packet)
|
||||
- Spoof victim’s device ID (**TODO**: How is it generated?)
|
||||
- Spoof KakaoTalk server
|
||||
- Spoof legitimate KakaoTalk LOCO notifications and messages
|
||||
- Send the attacker's public key to the victim (maybe there’s a LOCO command for updating RSA public keys on the client?)
|
||||
- MITM traffic
|
||||
- Tamper messages (CFB malleability —> [Efail](https://jaads.de/Bachelorthesis/Bachelorthesis_Jan_Arends.pdf))
|
||||
- [Owncloud CFB malleability bug](https://blog.hboeck.de/archives/880-Pwncloud-bad-crypto-in-the-Owncloud-encryption-module.html)
|
||||
- Use the `LOGINLIST` command with `chatDatas`, `attachment` or `code` JSON fields to run code on the client app?
|
||||
- Replay messages
|
||||
- Drop messages
|
||||
- Sniff plaintext LOCO packets (`CHECKIN` packet)
|
||||
- Downgrade attacks (maybe there's a way to fallback to unencrypted comms?)
|
||||
|
||||
### LOCO Message Parsing ("Zero Click")
|
||||
|
||||
- **TODO**: Build Kakaotalk Python app
|
||||
- Send a chat message to a victim to retrieve the E2E encryption key -> code injection
|
||||
- URL rendering
|
||||
- Calendar invite rendering
|
||||
- Emojis
|
||||
- Button rendering
|
||||
- Intents
|
||||
- Exploit (JSON) deserialization bugs
|
||||
|
||||
### Malicious third-party app
|
||||
|
||||
- Install a malcious app on the victim's device to retrieve the E2E key via IPC
|
||||
- Send malicious intents (code injection)
|
||||
- Spoof the Kakaotalk app
|
||||
|
||||
### Operator-side Attacks
|
||||
|
||||
- Operator-side MITM (e.g., by changing public keys)
|
||||
> There are a lot of **TO-DO's** in this document where one can try to dig deeper.
|
||||
|
||||
## General App Infos
|
||||
|
||||
|
|
@ -210,7 +130,7 @@ e31.ReAuthService
|
|||
p360hh.AuthApi
|
||||
```
|
||||
|
||||
There are [Google API Keys](./recon/nuclei_keys_results.txt) which allow access to the Google Maps API. Unauthorized access might cost the company some money.
|
||||
There are [Google API Keys](./recon/nuclei_keys_results.txt) which allow access to the Google Maps API. Unauthorized access might cost the company some money ([example](https://maps.googleapis.com/maps/api/staticmap?center=Z%C3%BCrich&zoom=12&size=400x400&key=AIzaSyC29Nja5CB6MoSQEWtzarrr5GIKvG8FtT4)).
|
||||
|
||||
## Activities
|
||||
|
||||
|
|
@ -453,27 +373,75 @@ Version: 3
|
|||
*******************************************
|
||||
```
|
||||
|
||||
### Secret Chat
|
||||
## Appendix
|
||||
|
||||
E2E is opt-in only. Most people probably don’t use Secret Chat since `In a secret chatrooom, features including free calling, polls, events and chatroom album are currently not available`.
|
||||
### Related Work
|
||||
|
||||
Main implementation in package `com.kakao.talk.secret` and the `LocoCipherHelper ` class.
|
||||
How things work:
|
||||
|
||||
MITM PoC:
|
||||
- [Kakaotalk Messaging Architecture](https://kth.diva-portal.org/smash/get/diva2:1046438/FULLTEXT01.pdf#page=75)
|
||||
- [User Registration and Login](https://kth.diva-portal.org/smash/get/diva2:1046438/FULLTEXT01.pdf#page=79)
|
||||
- [LOCO protocol](https://kth.diva-portal.org/smash/get/diva2:1046438/FULLTEXT01.pdf#page=77)
|
||||
|
||||
- Sender's RSA public key pair in `TalkKeyStore.preferences.xml`
|
||||
- Receiver's public keys in `KakaoTalk.db`
|
||||
- PoC how-to:
|
||||
- Delete all public keys from `KakaoTalk.db` database
|
||||
- Start mitmproxy and Frida script
|
||||
- Create new Secret Chat room
|
||||
- `GETLPK` packet gets intercepted -> Maybe we don't need that?
|
||||
- `SCREATE` packet gets intercepted (shouldn't include a shared secret, otherwise we remove it)
|
||||
- Bad signature check of MITM public key doesn't seem to have any implications
|
||||
- Sender sends a `SETSK` packet (mitmproxy grabs shared secret)
|
||||
- Dump `SWRITE` packets
|
||||
Flaws:
|
||||
|
||||
Questions:
|
||||
- How to attack an already existing E2E chat room?
|
||||
- How to fix maldformed `SCREATE` packets?
|
||||
- Check public key fingerprints if they have changed
|
||||
- [Protocol flaws](https://kth.diva-portal.org/smash/get/diva2:1046438/FULLTEXT01.pdf#page=100)
|
||||
- [App security flaws](https://kth.diva-portal.org/smash/get/diva2:1046438/FULLTEXT01.pdf#page=105)
|
||||
|
||||
### Attack Vector Brainstorming
|
||||
|
||||
#### Registration and Login
|
||||
|
||||
- Register an attacker's device to the victim's KakaoTalk account
|
||||
- Get victims account credentials email/pw (e.g., via a data dump on breached.vc)
|
||||
- Brute-force 4-digit pin
|
||||
- Intercept SMS during registration to get the pincode (e.g., via SS7 access)
|
||||
- Register an attacker's device via flaws in the LOCO protocol (`CHECKIN` and `LOGINLIST` commands maybe?)
|
||||
- Check out insecure REST API endpoints for authorization flaws
|
||||
- Check out QR Code login (`xm.a` and `vm.q` decompiled Java classes in jadx)
|
||||
- endpoint: `/talk/account/qrCodeLogin/info.json?id=eyJwcm90b2NvbCI6InYxIiwiY2hhbGxlbmdlIjoiNlB6MFMzdkRQMmlFUTZoRXh5YW5mWGtOelNHU0RRIn0=`
|
||||
- `{"protocol":"v1","challenge":"6Pz0S3vDP2iEQ6hExyanfXkNzSGSDQ"}`
|
||||
- `m.w.R1` method computes a MAC of the challenge
|
||||
- The OAuth refresh token seems to be the MAC key
|
||||
- How to obtain them? How are they generated? How long do they live?
|
||||
- `ym.a` class builds the POST request
|
||||
- API endpoints in interface `e31.j`
|
||||
- Test PW reset functionality
|
||||
|
||||
#### Cloud
|
||||
|
||||
- Cloud backup (weak password)
|
||||
- Secret Chat messages won't be stored
|
||||
- Tamper with plaintext asset downloads via HTTP (parser attacks on the client app possible?)
|
||||
|
||||
#### LOCO Protocol Attacks
|
||||
|
||||
- Spoof victim (`CHECKIN` packet)
|
||||
- Spoof victim’s device ID (**TODO**: How is it generated?)
|
||||
- Spoof KakaoTalk server
|
||||
- Spoof legitimate KakaoTalk LOCO notifications and messages
|
||||
- Send the attacker's public key to the victim (maybe there's a LOCO command for updating RSA public keys on the client?)
|
||||
- MITM traffic
|
||||
- Tamper messages (CFB malleability —> [Efail](https://jaads.de/Bachelorthesis/Bachelorthesis_Jan_Arends.pdf))
|
||||
- [Owncloud CFB malleability bug](https://blog.hboeck.de/archives/880-Pwncloud-bad-crypto-in-the-Owncloud-encryption-module.html)
|
||||
- Use the `LOGINLIST` command with `chatDatas`, `attachment` or `code` JSON fields to run code on the client app?
|
||||
- Replay messages
|
||||
- Drop messages
|
||||
- Sniff plaintext LOCO packets (`CHECKIN` packet)
|
||||
- Downgrade attacks (maybe there's a way to fallback to unencrypted communications?)
|
||||
|
||||
#### LOCO Message Parsing ("Zero Click")
|
||||
|
||||
- Send a chat message to a victim to retrieve the E2E encryption key -> code injection
|
||||
- URL rendering
|
||||
- Calendar invite rendering
|
||||
- Emojis
|
||||
- Button rendering
|
||||
- Intents
|
||||
- (JSON) deserialization bugs
|
||||
|
||||
#### Malicious third-party app
|
||||
|
||||
- Install a malcious app on the victim's device to retrieve the E2E key via IPC
|
||||
- Send malicious intents (code injection)
|
||||
- Spoof the Kakaotalk app
|
||||
Loading…
Reference in New Issue
Block a user