Deserialization of Untrusted Data Affecting c1cms.assemblies Open this link in a new tab package, versions [,6.12.8122.18346)

  • Attack Complexity


  • Availability


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  • snyk-id


  • published

    10 Apr 2022

  • disclosed

    30 Mar 2022

  • credit

    Jaroslav Lobačevski (@JarLob)

How to fix?

Upgrade C1CMS.Assemblies to version 6.12.8122.18346 or higher.


C1CMS.Assemblies is a .NET based Web Content Management System.

Affected versions of this package are vulnerable to Deserialization of Untrusted Data leading to an authenticated user causing the server to make arbitrary GET requests to other servers in the local network or on localhost. The attacker may also truncate arbitrary files to zero size (effectively delete them) leading to a denial of service (DoS) or altering application logic. The authenticated user may unknowingly perform the actions by visiting a specially crafted site.


Serialization is a process of converting an object into a sequence of bytes which can be persisted to a disk or database or can be sent through streams. The reverse process of creating object from sequence of bytes is called deserialization. Serialization is commonly used for communication (sharing objects between multiple hosts) and persistence (store the object state in a file or a database). It is an integral part of popular protocols like Remote Method Invocation (RMI), Java Management Extension (JMX), Java Messaging System (JMS), Action Message Format (AMF), Java Server Faces (JSF) ViewState, etc.

Deserialization of untrusted data (CWE-502) is when the application deserializes untrusted data without sufficiently verifying that the resulting data will be valid, thus allowing the attacker to control the state or the flow of the execution.