CVE-2025-21596 Junos OS: SRX1500,SRX4100,SRX4200: Execution of low-privileged CLI command results in chassisd crash
A local low-privileged attacker can crash the chassis daemon via a CLI command, causing a denial of service on Juniper SRX devices.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2025-21596?
CVE-2025-21596 is a medium-severity denial of service vulnerability in Juniper Junos, published on 9 Jan 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
An Improper Handling of Exceptional Conditions vulnerability in the command-line processing of Juniper Networks Junos OS on SRX1500, SRX4100, and SRX4200 devices allows a local, low-privileged authenticated attacker executing the 'show chassis environment pem' command to cause the chassis daemon (chassisd) to crash and restart, resulting in a temporary Denial of Service (DoS). However, repeated execution of this command will eventually cause the chassisd process to fail to restart, impacting packet processing on the system.
This issue affects Junos OS on SRX1500, SRX4100, SRX4200:
* All versions before 21.4R3-S9, * from 22.2 before 22.2R3-S5, * from 22.3 before 22.3R3-S4, * from 22.4 before 22.4R3-S4, * from 23.2 before 23.2R2-S3, * from 23.4 before 23.4R2-S1.
Weakness: CWE-755
Which versions are affected by CVE-2025-21596?
It affects 1 product.
Products include Juniper Junos.
How do I fix CVE-2025-21596?
No fix has been published for CVE-2025-21596 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2025-21596 being exploited?
There is no known exploitation of CVE-2025-21596 in the wild and no public exploit code.
Other vulnerabilities in Juniper Junos
- CVE-2023-36845 Juniper Junos OS EX Series and SRX Series PHP External Variable Modification
- CVE-2020-1631 Juniper Junos OS Path Traversal
- CVE-2025-21590 Juniper Junos OS Improper Isolation or Compartmentalization
- CVE-2023-36851 Juniper Junos OS SRX Series Missing Authentication for Critical Function
- CVE-2023-36844 Juniper Junos OS EX Series PHP External Variable Modification
Sources
Also known as GHSA-rxq5-5w2f-g92r.