CVE-2023-36848 Junos OS: MX Series: The FPC will crash on receiving a malformed CFM packet

Medium 6.5 Published 14 Jul 2023 Updated 22 Oct 2024

An unauthenticated adjacent attacker can cause a sustained denial of service on Juniper MX Series devices by sending malformed CFM packets if CFM is configured.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Local or same network only
Victim action needed: Not needed
Fix: None listed

What is CVE-2023-36848?

CVE-2023-36848 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 Improper Handling of Undefined Values vulnerability in the periodic packet management daemon (PPMD) of Juniper Networks Junos OS on MX Series(except MPC10, MPC11 and LC9600) allows an unauthenticated adjacent attacker to cause a Denial of Service (DoS).

When a malformed CFM packet is received, it leads to an FPC crash. Continued receipt of these packets causes a sustained denial of service. This vulnerability occurs only when CFM has been configured on the interface.

This issue affects Juniper Networks Junos OS: versions prior to 19.1R3-S10 on MX Series; 19.2 versions prior to 19.2R3-S7 on MX Series; 19.3 versions prior to 19.3R3-S8 on MX Series; 19.4 versions prior to 19.4R3-S12 on MX Series; 20.1 version 20.1R1 and later versions on MX Series; 20.2 versions prior to 20.2R3-S8 on MX Series; 20.3 version 20.3R1 and later versions on MX Series; 20.4 versions prior to 20.4R3-S7 on MX Series; 21.1 versions prior to 21.1R3-S5 on MX Series; 21.2 versions prior to 21.2R3-S5 on MX Series; 21.3 versions prior to 21.3R3-S4 on MX Series; 21.4 versions prior to 21.4R3-S4 on MX Series; 22.1 versions prior to 22.1R3-S3 on MX Series; 22.2 versions prior to 22.2R3-S1 on MX Series; 22.3 versions prior to 22.3R3 on MX Series; 22.4 versions prior to 22.4R1-S2, 22.4R2 on MX Series.

Weakness: CWE-232

Which versions are affected by CVE-2023-36848?

It affects 1 product.

Products include Juniper Junos.

How do I fix CVE-2023-36848?

No fix has been published for CVE-2023-36848 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-2023-36848 being exploited?

There is no known exploitation of CVE-2023-36848 in the wild and no public exploit code.

All Juniper Junos vulnerabilities

Sources

Also known as GHSA-pv7q-j2wh-2hh7.