CVE-2025-30646: Junos OS and Junos OS Evolved: Receipt of a malformed LLDP TLV results in l2cpd crash
First published: Wed Apr 09 2025(Updated: )
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.
Credit: sirt@juniper.net
| Affected Software | Affected Version | How to fix |
|---|---|---|
| Juniper JUNOS | <21.2R3-S9>=undefined>=undefined>=undefined>=undefined>=undefined>=undefined | |
| Juniper Networks Junos OS | <21.4R3-S10-EVO>=undefined>=undefined>=undefined>=undefined>=undefined |
Remedy
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.
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Reference Links
Frequently Asked Questions
What is the severity of CVE-2025-30646?
CVE-2025-30646 has been classified as a high severity vulnerability.
How do I fix CVE-2025-30646?
To mitigate CVE-2025-30646, apply the security patches provided by Juniper for affected versions of Junos OS.
Who is affected by CVE-2025-30646?
CVE-2025-30646 affects Juniper Networks Junos OS versions up to 21.2R3-S9 and Junos OS Evolved versions up to 21.4R3-S10-EVO.
What does CVE-2025-30646 exploit?
CVE-2025-30646 exploits a signed to unsigned conversion error in the Layer 2 Control Protocol daemon.
What type of attack can CVE-2025-30646 facilitate?
CVE-2025-30646 allows an unauthenticated adjacent attacker to disrupt the l2cpd process by sending a specifically malformed LLDP TLV.
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