Headline
CVE-2022-23535: Adding testing for Process object deserializaion rule · mbdavid/LiteDB@4382ff4
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.
@@ -170,7 +170,20 @@ public object Deserialize(Type type, BsonValue value)
var actualType = _typeNameBinder.GetType(typeField.AsString);
if (actualType == null) throw LiteException.InvalidTypedName(typeField.AsString);
if (!type.IsAssignableFrom(actualType)) throw LiteException.DataTypeNotAssignable(type.FullName, actualType.FullName);
// avoid initialize class that are not assignable
if (!type.IsAssignableFrom(actualType))
{
throw LiteException.DataTypeNotAssignable(type.FullName, actualType.FullName);
}
// avoid use of “System.Diagnostics.Process” in object type definition
// using String test to work in .netstandard 1.3
if (actualType.FullName.Equals("System.Diagnostics.Process", StringComparison.OrdinalIgnoreCase) &&
actualType.Assembly.GetName().Name.Equals("System", StringComparison.OrdinalIgnoreCase))
{
throw LiteException.AvoidUseOfProcess();
}
type = actualType;
}
Related news
### 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; } ...