CVE Vulnerabilities

CVE-2021-22097

Deserialization of Untrusted Data

Published: Oct 28, 2021 | Modified: Nov 01, 2021
CVSS 3.x
6.5
MEDIUM
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CVSS 2.x
6.8 MEDIUM
AV:N/AC:L/Au:S/C:N/I:N/A:C
RedHat/V2
RedHat/V3
Ubuntu

In Spring AMQP versions 2.2.0 - 2.2.18 and 2.3.0 - 2.3.10, the Spring AMQP Message object, in its toString() method, will deserialize a body for a message with content type application/x-java-serialized-object. It is possible to construct a malicious java.util.Dictionary object that can cause 100% CPU usage in the application if the toString() method is called.

Weakness

The product deserializes untrusted data without sufficiently verifying that the resulting data will be valid.

Affected Software

Name Vendor Start Version End Version
Spring_advanced_message_queuing_protocol Vmware 2.2.0 2.2.18
Spring_advanced_message_queuing_protocol Vmware 2.3.0 2.3.10

Extended Description

It is often convenient to serialize objects for communication or to save them for later use. However, deserialized data or code can often be modified without using the provided accessor functions if it does not use cryptography to protect itself. Furthermore, any cryptography would still be client-side security – which is a dangerous security assumption. Data that is untrusted can not be trusted to be well-formed. When developers place no restrictions on “gadget chains,” or series of instances and method invocations that can self-execute during the deserialization process (i.e., before the object is returned to the caller), it is sometimes possible for attackers to leverage them to perform unauthorized actions, like generating a shell.

Potential Mitigations

  • Make fields transient to protect them from deserialization.
  • An attempt to serialize and then deserialize a class containing transient fields will result in NULLs where the transient data should be. This is an excellent way to prevent time, environment-based, or sensitive variables from being carried over and used improperly.

References