CVE Vulnerabilities

CVE-2025-20276

Deserialization of Untrusted Data

Published: Jun 04, 2025 | Modified: Jun 04, 2025
CVSS 3.x
N/A
Source:
NVD
CVSS 2.x
RedHat/V2
RedHat/V3
Ubuntu

A vulnerability in the web-based management interface of Cisco Unified CCX could allow an authenticated, remote attacker to execute arbitrary code on an affected device. To exploit this vulnerability, the attacker must have valid administrative credentials. 

This vulnerability is due to insecure deserialization of Java objects by the affected software. An attacker could exploit this vulnerability by sending a crafted Java object to an affected device. A successful exploit could allow the attacker to execute arbitrary code on the underlying operating system of an affected device as a low-privilege user. A successful exploit could also allow the attacker to undertake further actions to elevate their privileges to root.

Weakness

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

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