CVE-2023-36838 Junos OS: SRX Series: A flowd core occurs when running a low privileged CLI command
A local authenticated attacker can cause a denial of service on Juniper SRX devices by triggering a flowd crash via a specific CLI command.
- 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-2023-36838?
CVE-2023-36838 is a medium-severity denial of service vulnerability in Juniper Junos, published on 14 Jul 2023. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
An Out-of-bounds Read vulnerability in the flow processing daemon (flowd) of Juniper Networks Junos OS on SRX Series allows a local, authenticated attacker with low privileges, to cause a Denial of Service (DoS).
If a low privileged user executes a specific CLI command, flowd which is responsible for traffic forwarding in SRX crashes and generates a core dump. This will cause temporary traffic interruption until the flowd process is restarted automatically. Continued execution of this command will lead to a sustained DoS.
This issue affects Juniper Networks Junos OS on SRX Series: All versions prior to 20.2R3-S7; 20.3 version 20.3R1 and later versions; 20.4 versions prior to 20.4R3-S6; 21.1 versions prior to 21.1R3-S5; 21.2 versions prior to 21.2R3-S4; 21.3 versions prior to 21.3R3-S4; 21.4 versions prior to 21.4R3-S3; 22.1 versions prior to 22.1R3-S1; 22.2 versions prior to 22.2R3; 22.3 versions prior to 22.3R2; 22.4 versions prior to 22.4R1-S1, 22.4R2.
Weakness: CWE-125
Which versions are affected by CVE-2023-36838?
It affects 1 product.
Products include Juniper Junos.
How do I fix CVE-2023-36838?
No fix has been published for CVE-2023-36838 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-2023-36838 being exploited?
There is no known exploitation of CVE-2023-36838 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-xfjj-5jcc-72cx.