CVE Vulnerabilities

CVE-2021-43297

Deserialization of Untrusted Data

Published: Jan 10, 2022 | Modified: Jan 18, 2022
CVSS 3.x
9.8
CRITICAL
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS 2.x
7.5 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P
RedHat/V2
RedHat/V3
Ubuntu

A deserialization vulnerability existed in dubbo hessian-lite 3.2.11 and its earlier versions, which could lead to malicious code execution. Most Dubbo users use Hessian2 as the default serialization/deserialization protocol, during Hessian catch unexpected exceptions, Hessian will log out some imformation for users, which may cause remote command execution. This issue affects Apache Dubbo Apache Dubbo 2.6.x versions prior to 2.6.12; Apache Dubbo 2.7.x versions prior to 2.7.15; Apache Dubbo 3.0.x versions prior to 3.0.5.

Weakness

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

Affected Software

Name Vendor Start Version End Version
Dubbo Apache 2.6.0 (including) 2.6.12 (excluding)
Dubbo Apache 2.7.0 (including) 2.7.15 (excluding)
Dubbo Apache 3.0.0 (including) 3.0.5 (excluding)

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