2025-04 Security Bulletin: Junos OS and Junos OS Evolved: Receipt of a malformed LLDP TLV results in l2cpd crash (CVE-2025-30646)

Product Affected

This issue affects all versions of Junos OS and Junos OS Evolved.

Severity

Medium

Severity Assessment (CVSS) Score

CVSS: v3.1: 6.5 (CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
CVSS: v4.0: 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:L/AU:Y/R:A/V:C/RE:M)

Problem

A Signed to Unsigned Conversion Error vulnerability in the Layer 2 Control Protocol daemon (l2cpd) of Juniper Networks Junos OS and Juniper Networks Junos OS Evolved allows an unauthenticated adjacent attacker sending a specifically malformed LLDP TLV to cause the l2cpd process to crash and restart, causing a Denial of Service (DoS). Continued receipt and processing of this packet will create a sustained Denial of Service (DoS) condition.

When an LLDP telemetry subscription is active, receipt of a specifically malformed LLDP TLV causes the l2cpd process to crash and restart.

This issue affects:

Junos OS:

All versions before 21.2R3-S9,
from 21.4 before 21.4R3-S10,
from 22.2 before 22.2R3-S6,
from 22.4 before 22.4R3-S6,
from 23.2 before 23.2R2-S3,
from 23.4 before 23.4R2-S4,
from 24.2 before 24.2R2;

Junos OS Evolved:

All versions before 21.4R3-S10-EVO,
from 22.2-EVO before 22.2R3-S6-EVO,
from 22.4-EVO before 22.4R3-S6-EVO,
from 23.2-EVO before 23.2R2-S3-EVO,
from 23.4-EVO before 23.4R2-S4-EVO,
from 24.2-EVO before 24.2R2-EVO.

Only systems configured for LLDP with active telemetry subscriptions are vulnerable to this issue:

[ protocols lldp ]

and:

[ system services extension-service request-response ]

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

This issue was found during internal product security testing or research.

Solution

The following software releases have been updated to resolve this specific issue:
Junos OS: 21.2R3-S9, 21.4R3-S10, 22.2R3-S6, 22.4R3-S6, 23.2R2-S3, 23.4R2-S4, 24.2R2, 24.4R1, and all subsequent releases.
Junos OS Evolved: 21.4R3-S10-EVO, 22.2R3-S6-EVO, 22.4R3-S6-EVO, 23.2R2-S3-EVO, 23.4R2-S4-EVO, 24.2R2-EVO, 24.4R1-EVO, and all subsequent releases.

This issue is being tracked as 1845098 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 known workarounds for this issue.

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