CVE-2024-21618

/// Technical description

An Access of Memory Location After End of Buffer vulnerability in the Layer-2 Control Protocols Daemon (l2cpd) of Juniper Networks Junos OS and Junos OS Evolved allows an adjacent, unauthenticated attacker to cause Denial of Service (DoS).

On all Junos OS and Junos OS Evolved platforms, when LLDP is enabled on a specific interface, and a malformed LLDP packet is received, l2cpd crashes and restarts. The impact of the l2cpd crash is reinitialization of STP protocols (RSTP, MSTP or VSTP), and MVRP and ERP. Also, if any services depend on LLDP state (like PoE or VoIP device recognition), then these will also be affected.

This issue affects:

Junos OS:

* from 21.4 before 21.4R3-S4, 

* from 22.1 before 22.1R3-S4, 

* from 22.2 before 22.2R3-S2, 

* from 22.3 before 22.3R2-S2, 22.3R3-S1, 

* from 22.4 before 22.4R3, 

* from 23.2 before 23.2R2.

Junos OS Evolved:

* from 21.4-EVO before 21.4R3-S5-EVO, 

* from 22.1-EVO before 22.1R3-S4-EVO, 

* from 22.2-EVO

/// 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