CVE-2024-21618

Adjacent l2cpd crash via malformed LLDP packet

Published Apr 12, 2024 · Updated Aug 1, 2024

Out-of-bounds memory access in Juniper Networks Junos OS and Junos OS Evolved allows attackers to crash and restart l2cpd. The daemon accesses memory beyond the end of a buffer while processing a malformed LLDP packet received on an enabled interface. An attacker must reach the same Layer 2 link and an LLDP-enabled interface; the restart reinitializes STP, MVRP, and ERP and disrupts LLDP-dependent services.

CVSS severity7.1
High
EPSS probability0.30%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds memory access in Juniper Networks Junos OS and Junos OS Evolved allows attackers to crash and restart l2cpd. The daemon accesses memory beyond the end of a buffer while processing a malformed LLDP packet received on an enabled interface. An attacker must reach the same Layer 2 link and an LLDP-enabled interface; the restart reinitializes STP, MVRP, and ERP and disrupts LLDP-dependent services.

The record

CVE
CVE-2024-21618
Published
Apr 12, 2024
Updated
Aug 1, 2024
Vendor
Juniper Networks
Product
Junos OS Evolved
Classifications
CWE-788, T1499.004
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 12, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 1, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=21.4-EVO <21.4R3-S5-EVO
  2. Affected versionversion=22.1-EVO <22.1R3-S4-EVO
  3. Affected versionversion=22.2-EVO <22.2R3-S2-EVO
  4. Affected versionversion=22.3-EVO <22.3R2-S2-EVO, 22.3R3-S1-EVO
  5. Affected versionversion=22.4-EVO <22.4R3-EVO
  6. Affected versionversion=23.2-EVO <23.2R2-EVO

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Juniper Networks · Junos OS Evolvedversion=21.4-EVO <21.4R3-S5-EVO; version=22.1-EVO <22.1R3-S4-EVO; version=22.2-EVO <22.2R3-S2-EVO; version=22.3-EVO <22.3R2-S2-EVO, 22.3R3-S1-EVO; version=22.4-EVO <22.4R3-EVO; version=23.2-EVO <23.2R2-EVO
Juniper Networks · Junos OSversion=21.4 <21.4R3-S4; version=22.1 <22.1R3-S4; version=22.2 <22.2R3-S2; version=22.3 <22.3R2-S2, 22.3R3-S1; version=22.4 <22.4R3; version=23.2 <23.2R2

Published CVSS scores

7.1Juniper NetworksCVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L
6.5Juniper NetworksCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-788Access of Memory Location After End of Buffer
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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