CVE-2022-23535

LiteDB is a small, fast and lightweight .NET NoSQL embedded database. Versions prior to 5.0.13 are subject to Deserialization of Untrusted Data. LiteDB uses a special field in JSON documents to cast different types from BsonDocument to POCO classes. When instances of an object are not the same of class, BsonMapper use a special field _type string info with full class name with assembly to be loaded and fit into your model. If your end-user can send to your app a plain JSON string, deserialization can load an unsafe object to fit into your model. This issue is patched in version 5.0.13 with some basic fixes to avoid this, but is not 100% guaranteed when using Object type. The next major version will contain an allow-list to select what kind of Assembly can be loaded. Workarounds are detailed in the vendor advisory.

LiteDB is a small, fast and lightweight .NET NoSQL embedded database. Versions prior to 5.0.13 are subject to Deserialization of Untrusted Data. LiteDB uses a special field in JSON documents to cast different types from BsonDocument to POCO classes. When instances of an object are not the same of class, BsonMapper use a special field _type string info with full class name with assembly to be loaded and fit into your model. If your end-user can send to your app a plain JSON string, deserialization can load an unsafe object to fit into your model. This issue is patched in version 5.0.13 with some basic fixes to avoid this, but is not 100% guaranteed when using Object type. The next major version will contain an allow-list to select what kind of Assembly can be loaded. Workarounds are detailed in the vendor advisory.

Impact

LiteDB use a special field in JSON documents to cast diferent types from BsonDocument do POCO classes. When instance of an object are not the same of class, BsonMapper use a special field _type string info with full class name with assembly to be loaded and fit in your model. If your end-user can send to your app a plain JSON string, deserialization can load an unsafe object to fit in your model.

Patches

Version >= 5.0.13 add some basic fixes to avoid this, but is not 100% guaranteed when using Object type Next major version will contains a allow-list to select what king of Assembly can be loaded

Workarounds

• Avoid users send to your app a JSON string to be direct insert/update into database
• Avoid use classes with Object type - try use an interface when possible

If your app send a plain JSON string to be insert/update into database, prefer this:

// Bad
public class Customer {
    public int Id { get; set; }
    public string Name { get; set; }
    public Object AnyData { get; set; } // <= Avoid use `Object` base type
}

// Good
public class Customer {
    public int Id { get; set; }
    public string Name { get; set; }
    public IDictionary<string, string> AnyData { get; set; } // Will accept only key/value strings
}

References

See this workaround fix on this commit:

https://github.com/mbdavid/LiteDB/commit/4382ff4dd0dd8b8b16a4e37dfd29727c5f70f93f

LiteDB is a small, fast and lightweight .NET NoSQL embedded database. Versions prior to 5.0.13 are subject to Deserialization of Untrusted Data. LiteDB uses a special field in JSON documents to cast different types from BsonDocument to POCO classes. When instances of an object are not the same of class, BsonMapper use a special field _type string info with full class name with assembly to be loaded and fit into your model. If your end-user can send to your app a plain JSON string, deserialization can load an unsafe object to fit into your model. This issue is patched in version 5.0.13 with some basic fixes to avoid this, but is not 100% guaranteed when using Object type. The next major version will contain an allow-list to select what kind of Assembly can be loaded. Workarounds are detailed in the vendor advisory.

LiteDB is a small, fast and lightweight .NET NoSQL embedded database. Versions prior to 5.0.13 are subject to Deserialization of Untrusted Data. LiteDB uses a special field in JSON documents to cast different types from BsonDocument to POCO classes. When instances of an object are not the same of class, BsonMapper use a special field _type string info with full class name with assembly to be loaded and fit into your model. If your end-user can send to your app a plain JSON string, deserialization can load an unsafe object to fit into your model. This issue is patched in version 5.0.13 with some basic fixes to avoid this, but is not 100% guaranteed when using Object type. The next major version will contain an allow-list to select what kind of Assembly can be loaded. Workarounds are detailed in the vendor advisory.

Impact

LiteDB use a special field in JSON documents to cast diferent types from BsonDocument do POCO classes. When instance of an object are not the same of class, BsonMapper use a special field _type string info with full class name with assembly to be loaded and fit in your model. If your end-user can send to your app a plain JSON string, deserialization can load an unsafe object to fit in your model.

Patches

Version >= 5.0.13 add some basic fixes to avoid this, but is not 100% guaranteed when using Object type Next major version will contains a allow-list to select what king of Assembly can be loaded

Workarounds

• Avoid users send to your app a JSON string to be direct insert/update into database
• Avoid use classes with Object type - try use an interface when possible

If your app send a plain JSON string to be insert/update into database, prefer this:

// Bad
public class Customer {
    public int Id { get; set; }
    public string Name { get; set; }
    public Object AnyData { get; set; } // <= Avoid use `Object` base type
}

// Good
public class Customer {
    public int Id { get; set; }
    public string Name { get; set; }
    public IDictionary<string, string> AnyData { get; set; } // Will accept only key/value strings
}

References

See this workaround fix on this commit:

https://github.com/mbdavid/LiteDB/commit/4382ff4dd0dd8b8b16a4e37dfd29727c5f70f93f