CVE-2023-36850

/// Technical description

An Improper Validation of Specified Index, Position, or Offset in Input vulnerability in the Connectivity Fault Management(CFM) module of Juniper Networks Junos OS on MX Series(except MPC10, MPC11 and LC9600) allows an adjacent attacker on the local broadcast domain to cause a Denial of Service(DoS).

Upon receiving a malformed CFM packet, the MPC crashes. Continued receipt of these packets causes a sustained denial of service. This issue can only be triggered when CFM hasn't been configured.

This issue affects:

Juniper Networks Junos OS

All 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-S7 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

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References