title: LiteDB contains Deserialization of Untrusted Data
description: 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.
problem types: CWE-502: Deserialization of Untrusted Data
affected:
{
vendor: mbdavid
product: LiteDB
versions:
version: < 5.0.13, status: affected
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: LOW
baseScore: 7.3
baseSeverity: HIGH
confidentialityImpact: LOW
integrityImpact: LOW
privilegesRequired: NONE
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
version: 3.1
]