CVE-2024-21618 Junos OS and Junos OS Evolved: When LLDP is enabled and a malformed LLDP packet is received, l2cpd crashes
An adjacent attacker can cause a denial of service by sending malformed LLDP packets to Junos OS devices with LLDP enabled.
- 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-2024-21618?
CVE-2024-21618 is a high-severity memory corruption vulnerability in Juniper Junos, published on 12 Apr 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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 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.
Which versions are affected by CVE-2024-21618?
It affects 2 products.
Products include Juniper Junos, Juniper Junos Os Evolved.
How do I fix CVE-2024-21618?
No fix has been published for CVE-2024-21618 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2024-21618 being exploited?
There is no known exploitation of CVE-2024-21618 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-6rj9-5jww-q88j.