CVE-2024-39559

Technical Description

An Improper Check for Unusual or Exceptional Conditions vulnerability in packet processing of Juniper Networks Junos OS Evolved may allow a network-based unauthenticated attacker to crash the device (vmcore) by sending a specific TCP packet over an established TCP session with MD5 authentication enabled, destined to an accessible port on the device, resulting in a Denial of Service (DoS).  The receipt of this packet must occur within a specific timing window outside the attacker's control (i.e., race condition).

Continued receipt and processing of this packet will create a sustained Denial of Service (DoS) condition.

This issue only affects dual RE systems with Nonstop Active Routing (NSR) enabled.

Exploitation can only occur over TCP sessions with MD5 authentication enabled (e.g., BGP with MD5 authentication).

This issue affects Junos OS Evolved: 

* All versions before 21.2R3-S8-EVO,

* from 21.4-EVO before 21.4R3-S6-EVO,

* from 22.1-EVO before 22.1R3-S4-EVO,

* fro

Remediation

Check the references section for vendor advisories and patches from juniper. Update junos_os_evolved to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

Affected Products

References