Junos OS and Junos OS Evolved: Receipt of a malformed LLDP TLV results in l2cpd crash

Summary

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.

Timeline

1. Apr 9, 2025, 7:53 PM UTCCVE published
2. Apr 9, 2025, 8:39 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: no · Technical impact: partial

3. Apr 9, 2025, 8:39 PM UTCRecord last updated

Affected versions

• Juniper Networks Junos OS

  fixed in 21.2R3-S9; From 21.4 · fixed in 21.4R3-S10; From 22.2 · fixed in 22.2R3-S6; From 22.4 · fixed in 22.4R3-S6; From 23.2 · fixed in 23.2R2-S3; From 23.4 · fixed in 23.4R2-S4; From 24.2 · fixed in 24.2R2

• Juniper Networks Junos OS Evolved

  fixed in 21.4R3-S10-EVO; From 22.2-EVO · fixed in 22.2R3-S6-EVO; From 22.4-EVO · fixed in 22.4R3-S6-EVO; From 23.2-EVO · fixed in 23.2R2-S3-EVO; From 23.4-EVO · fixed in 23.4R2-S4-EVO; From 24.2-EVO · fixed in 24.2R2-EVO

References 1