Juniper Junos OS: 2024-04 Security Bulletin: Junos OS and Junos OS Evolved: When LLDP is enabled and a malformed LLDP packet is received, l2cpd crashes (JSA75759) (CVE-2024-21618)

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 before 22.2R3-S2-EVO, 

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

* from 22.4-EVO before 22.4R3-EVO, 

* from 23.2-EVO before 23.2R2-EVO.

This issue does not affect:
* Junos OS versions prior to 21.4R1;

* Junos OS Evolved versions prior to 21.4R1-EVO.