CVE Vulnerabilities

CVE-2020-4305

Deserialization of Untrusted Data

Published: Jul 09, 2020 | Modified: Jul 17, 2020
CVSS 3.x
8.8
HIGH
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS 2.x
9.3 HIGH
AV:N/AC:M/Au:N/C:C/I:C/A:C
RedHat/V2
RedHat/V3
Ubuntu

IBM InfoSphere Information Server 11.3, 11.5, and 11.7 could allow a remote attacker to execute arbitrary code on the system, caused by the deserialization of untrusted data. By persuading a victim to visit a specially crafted Web site, an attacker could exploit this vulnerability to execute arbitrary code on the system. IBM X-Force ID: 176677.

Weakness

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

Affected Software

Name Vendor Start Version End Version
Infosphere_information_server Ibm 11.7.0.0 (including) 11.7.1.1 (including)
Infosphere_information_server Ibm 11.3.0 (including) 11.3.0 (including)
Infosphere_information_server Ibm 11.5.0 (including) 11.5.0 (including)
Infosphere_information_server_on_cloud Ibm 11.7.0.0 (including) 11.7.1.1 (including)
Infosphere_information_server_on_cloud Ibm 11.5.0.0 (including) 11.5.0.0 (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