CVE-2024-39559 Race condition in Junos OS Evolved
An unauthenticated attacker can crash dual RE Junos OS Evolved systems with NSR enabled by sending specific TCP packets during a race condition window.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2024-39559?
CVE-2024-39559 is a high-severity vulnerability in Juniper Junos Os Evolved, published on 10 Jul 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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, * from 22.2-EVO before 22.2R3-S4-EVO, * from 22.3-EVO before 22.3R3-S3-EVO, * from 22.4-EVO before 22.4R2-S2-EVO, 22.4R3-EVO.
Weakness: CWE-754
Which versions are affected by CVE-2024-39559?
It affects 1 product.
Products include Juniper Junos Os Evolved.
How do I fix CVE-2024-39559?
No fix has been published for CVE-2024-39559 yet. Limit exposure of the affected software until one is available.
Is CVE-2024-39559 being exploited?
There is no known exploitation of CVE-2024-39559 in the wild and no public exploit code.
Other vulnerabilities in Juniper Junos Os Evolved
- CVE-2026-21902 Junos OS Evolved: PTX Series: A vulnerability allows a unauthenticated, network-based attacker to execute code as root
- CVE-2023-28983 Junos OS Evolved: Shell Injection vulnerability in the gNOI server
- CVE-2025-21599 Denial of service in Junos OS Evolved
- CVE-2024-47502 Junos OS Evolved: TCP session state is not always cleared on the Routing Engine leading to DoS
- CVE-2024-39531 Junos OS Evolved: ACX 7000 Series: Protocol specific DDoS configuration affects other protocols
Sources
Also known as GHSA-473h-3vgg-7379.