CVE Vulnerabilities

CVE-2022-39311

Deserialization of Untrusted Data

Published: Oct 14, 2022 | Modified: Oct 19, 2022
CVSS 3.x
8.8
HIGH
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS 2.x
RedHat/V2
RedHat/V3
Ubuntu

GoCD is a continuous delivery server. GoCD helps you automate and streamline the build-test-release cycle for continuous delivery of your product. GoCD versions prior to 21.1.0 are vulnerable to remote code execution on the server from a malicious or compromised agent. The Spring RemoteInvocation endpoint exposed agent communication and allowed deserialization of arbitrary java objects, as well as subsequent remote code execution. Exploitation requires agent-level authentication, thus an attacker would need to either compromise an existing agent, its network communication or register a new agent to practically exploit this vulnerability. This issue is fixed in GoCD version 21.1.0. There are currently no known workarounds.

Weakness

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

Affected Software

Name Vendor Start Version End Version
Gocd Thoughtworks * 21.1.0 (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