CVE Vulnerabilities

CVE-2021-41616

Deserialization of Untrusted Data

Published: Sep 30, 2021 | Modified: Oct 07, 2021
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

Apache DB DdlUtils 1.0 included a BinaryObjectsHelper that was intended for use when migrating database data with a SQL data type of BINARY, VARBINARY, LONGVARBINARY, or BLOB between databases using the ddlutils features. The BinaryObjectsHelper class was insecure and used ObjectInputStream.readObject without validating that the input data was safe to deserialize. Please note that DdlUtils is no longer being actively developed. To address the insecurity of the BinaryObjectHelper class, the following changes to DdlUtils have been made: (1) BinaryObjectsHelper.java has been deleted from the DdlUtils source repository and the DdlUtils feature of propagating data of SQL binary types is therefore no longer present in DdlUtils; (2) The ddlutils-1.0 release has been removed from the Apache Release Distribution Infrastructure; (3) The DdlUtils web site has been updated to indicate that DdlUtils is now available only as source code, not as a packaged release.

Weakness

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

Affected Software

Name Vendor Start Version End Version
Ddlutils Apache 1.0 (including) 1.0 (including)

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