CVE Vulnerabilities

CVE-2019-14439

Deserialization of Untrusted Data

Published: Jul 30, 2019 | Modified: Nov 07, 2023
CVSS 3.x
7.5
HIGH
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CVSS 2.x
5 MEDIUM
AV:N/AC:L/Au:N/C:P/I:N/A:N
RedHat/V2
RedHat/V3
7.5 MODERATE
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Ubuntu
MEDIUM

A Polymorphic Typing issue was discovered in FasterXML jackson-databind 2.x before 2.9.9.2. This occurs when Default Typing is enabled (either globally or for a specific property) for an externally exposed JSON endpoint and the service has the logback jar in the classpath.

Weakness

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

Affected Software

Name Vendor Start Version End Version
Jackson-databind Fasterxml 2.0.0 (including) 2.6.7.3 (excluding)
Jackson-databind Fasterxml 2.7.0 (including) 2.7.9.6 (excluding)
Jackson-databind Fasterxml 2.8.0 (including) 2.8.11.4 (excluding)
Jackson-databind Fasterxml 2.9.0 (including) 2.9.9.2 (excluding)
Red Hat AMQ Streams 1 RedHat jackson-databind *
Red Hat Fuse 7.6.0 RedHat jackson-databind *
Jackson-databind Ubuntu bionic *
Jackson-databind Ubuntu disco *
Jackson-databind Ubuntu esm-apps/bionic *
Jackson-databind Ubuntu esm-apps/xenial *
Jackson-databind Ubuntu trusty *
Jackson-databind Ubuntu xenial *

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