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Product Affected

This issue affects Junos OS 21.4, 22.1, 22.2, 22.3, 22.4, 23.2. This issue affects Junos OS Evolved 21.4-EVO, 22.1-EVO, 22.2-EVO, 22.3-EVO, 22.4-EVO, 23.2-EVO.

Severity

Medium

Severity Assessment (CVSS) Score

CVSS 3.1: 6.5 (CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

CVSS 4.0: 7.1 (CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N)

Problem

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 before 21.4R1;
Junos OS Evolved versions before 21.4R1-EVO.

This vulnerability is only exploitable on interfaces with LLDP enabled.

[protocols lldp interface]

Juniper SIRT is not aware of any malicious exploitation of this vulnerability.

This issue was discovered during production use.

This issue has been assigned CVE-2024-21618.

Solution

The following software releases have been updated to resolve this specific issue:

Junos OS: 21.4R3-S4, 22.1R3-S4, 22.2R3-S2, 22.3R2-S2, 22.3R3-S1, 22.4R3, 23.2R2, 23.4R1 and all subsequent releases.

Junos OS Evolved: 21.4R3-S5-EVO, 22.1R3-S4-EVO, 22.2R3-S2-EVO, 22.3R2-S2-EVO, 22.3R3-S1-EVO, 22.4R3-EVO, 23.2R2-EVO, 23.4R1-EVO and all subsequent releases.

This issue is being tracked as 1747039 which is visible on the Customer Support website.

Note: Juniper SIRT's policy is not to evaluate releases which are beyond End of Engineering (EOE) or End of Life (EOL).

Workaround

There are no available workarounds for this issue.

But if LLDP and its services are not required, customers can disable LLDP.

Severity Assessment

Information for how Juniper Networks uses CVSS can be found at KB 16446 [juniper.net] "Common Vulnerability Scoring System (CVSS) and Juniper's Security Advisories."

Modification History