CVE Vulnerabilities

CVE-2020-13092

Deserialization of Untrusted Data

Published: May 15, 2020 | Modified: May 17, 2024
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
NEGLIGIBLE

scikit-learn (aka sklearn) through 0.23.0 can unserialize and execute commands from an untrusted file that is passed to the joblib.load() function, if reduce makes an os.system call. NOTE: third parties dispute this issue because the joblib.load() function is documented as unsafe and it is the users responsibility to use the function in a secure manner

Weakness

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

Affected Software

Name Vendor Start Version End Version
Scikit-learn Scikit-learn * 0.23.0 (including)
Scikit-learn Ubuntu bionic *
Scikit-learn Ubuntu eoan *
Scikit-learn Ubuntu groovy *
Scikit-learn Ubuntu hirsute *
Scikit-learn Ubuntu impish *
Scikit-learn Ubuntu kinetic *
Scikit-learn Ubuntu lunar *
Scikit-learn Ubuntu mantic *
Scikit-learn Ubuntu trusty *
Scikit-learn 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