CVE-2024-21603 Junos OS: MX Series: Gathering statistics in a scaled SCU/DCU configuration will lead to a device crash
A network-based attacker with low privileges can cause a device crash and sustained denial of service on specific Juniper MX Series devices by triggering kernel exceptions during statistics gathering.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2024-21603?
CVE-2024-21603 is a medium-severity denial of service vulnerability in Juniper Junos, published on 12 Jan 2024. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
An Improper Check for Unusual or Exceptional Conditions vulnerability in the kernel of Juniper Network Junos OS on MX Series allows a network based attacker with low privileges to cause a denial of service.
If a scaled configuration for Source class usage (SCU) / destination class usage (DCU) (more than 10 route classes) is present and the SCU/DCU statistics are gathered by executing specific SNMP requests or CLI commands, a 'vmcore' for the RE kernel will be seen which leads to a device restart. Continued exploitation of this issue will lead to a sustained DoS.
This issue only affects MX Series devices with MPC10, MPC11 or LC9600, and MX304. No other MX Series devices are affected.
This issue affects Juniper Networks Junos OS:
* All versions earlier than 20.4R3-S9; * 21.2 versions earlier than 21.2R3-S6; * 21.3 versions earlier than 21.3R3-S5; * 21.4 versions earlier than 21.4R3; * 22.1 versions earlier than 22.1R3; * 22.2 versions earlier than 22.2R2; * 22.3 versions earlier than 22.3R2.
Weakness: CWE-754
Which versions are affected by CVE-2024-21603?
It affects 1 product.
Products include Juniper Junos.
How do I fix CVE-2024-21603?
No fix has been published for CVE-2024-21603 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-2024-21603 being exploited?
There is no known exploitation of CVE-2024-21603 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-f572-5hm8-87qp.