CVE-2022-22172

Junos OS and Junos OS Evolved: An l2cpd memory leak can occur when specific LLDP packets are received leading to a DoS

MEDIUM

6.5

CVSS Score

Published: January 19, 2022 at 12:21 AM UTC

Updated: June 17, 2026 at 04:27 AM UTC

3 products affected across 2 vendorsJunosJunos OS EvolvedJunos OS Evolved

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Severity

MEDIUM6.5

Exploit prediction

EPSS 0.4%

Description

A Missing Release of Memory after Effective Lifetime vulnerability in the Layer-2 control protocols daemon (l2cpd) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated adjacent attacker to cause a memory leak. Continued exploitation can lead to memory exhaustion and thereby a Denial of Service (DoS). This issue occurs when specific LLDP packets are received. The impact of the l2cpd cores is that if any of the stp protocols (rstp, mstp or vstp) is used then stp re-converges and traffic loss will occur during that time. Also if any services depend on LLDP state (like PoE or VoIP device recognition) then these will also be affected. The memory utilization of the L2CPd process can be monitored with the following command: user@host> show system processes extensive | match l2cpd 1234 root 52 0 521M 43412K RUN 1 4:02 34.47% l2cpd This issue affects: Juniper Networks Junos OS 18.4 version 18.4R2-S4 and later versions prior to 18.4R2-S10. 19.2 versions prior to 19.2R1-S8, 19.2R3-S4; 19.3 versions prior to 19.3R3-S5; 19.4 versions prior to 19.4R3-S7; 20.1 versions prior to 20.1R3-S3; 20.2 versions prior to 20.2R3-S2; 20.3 versions prior to 20.3R3-S1; 20.4 versions prior to 20.4R3; 21.1 versions prior to 21.1R2-S2, 21.1R3; 21.2 versions prior to 21.2R2; Juniper Networks Junos OS Evolved All versions prior to 20.4R3-S2-EVO; 21.1 version 21.1R1-EVO and later versions; 21.2 versions prior to 21.2R2-EVO. This issue does not affect: Juniper Networks Junos OS 19.1 version 19.1R1 and later versions.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Junos OS Evolved · Juniper

95%

20.4 r1 20.4 r1-s1 20.4 r1-s2 20.4 r2 20.4 r2-s1 20.4 r2-s2 20.4 r2-s3 20.4 r3 20.4 r3-s1 21.1 21.1 r1 21.1 r1-s1 21.1 r2 21.2 r1 21.2 r1-s1 21.2 r2

Junos · Juniper Networks

95%

18.4R2-S4 ≤ v < 18.4*19.2 ≤ v < 19.2R1-S8, 19.2R3-S419.3 ≤ v < 19.3R3-S519.4 ≤ v < 19.4R3-S720.1 ≤ v < 20.1R3-S320.2 ≤ v < 20.2R3-S220.3 ≤ v < 20.3R3-S120.4 ≤ v < 20.4R321.1 ≤ v < 21.1R2-S2, 21.1R321.2 ≤ v < 21.2R218.4 r2-s4 18.4 r2-s5 18.4 r2-s6 18.4 r2-s7 18.4 r2-s8 18.4 r2-s9 18.4R2-S4 19.2 19.2 r1 19.2 r1-s1 19.2 r1-s2 19.2 r1-s3 19.2 r1-s4 19.2 r1-s5 19.2 r1-s6 19.2 r1-s7 19.2 r3 19.2 r3-s1 19.2 r3-s2 19.2 r3-s3 19.3 19.3 r1 19.3 r1-s1 19.3 r2 19.3 r2-s1 19.3 r2-s2 19.3 r2-s3 19.3 r2-s4 19.3 r2-s5 19.3 r2-s6 19.3 r3-s4 19.4 19.4 r1 19.4 r1-s1 19.4 r1-s2 19.4 r1-s3 19.4 r1-s4 19.4 r2 19.4 r2-s1 19.4 r2-s2 19.4 r2-s3 19.4 r2-s4 19.4 r2-s5 19.4 r3 19.4 r3-s1 19.4 r3-s2 19.4 r3-s3 19.4 r3-s4 19.4 r3-s5 19.4 r3-s6 20.1 20.1 r1 20.1 r1-s1 20.1 r1-s2 20.1 r1-s3 20.1 r1-s4 20.1 r2 20.1 r2-s1 20.1 r2-s2 20.1 r3 20.1 r3-s1 20.1 r3-s2 20.2 20.2 r1 20.2 r1-s1 20.2 r1-s2 20.2 r1-s3 20.2 r2 20.2 r2-s1 20.2 r2-s2 20.2 r2-s3 20.2 r3 20.2 r3-s1 20.3 20.3 r1 20.3 r1-s1 20.3 r2 20.3 r2-s1 20.3 r3 20.4 20.4 r1 20.4 r1-s1 20.4 r2 20.4 r2-s1 20.4 r2-s2 21.1 21.1 r1 21.1 r1-s1 21.1 r2 21.1 r2-s1 21.2 21.2 r1 21.2 r1-s1 21.2 r1-s2

Affected range stops below 18.4*, so it looks safe — our inference, not a vendor statement

Vendor states this is fixed in 18.4R2-S4 (unaffected)

Vendor states this is fixed in 19.1R1 (unaffected)

Affected range stops below 19.2R1-S8, 19.2R3-S4, so it looks safe — our inference, not a vendor statement

Affected range stops below 19.3R3-S5, so it looks safe — our inference, not a vendor statement

Affected range stops below 19.4R3-S7, so it looks safe — our inference, not a vendor statement

Affected range stops below 20.1R3-S3, so it looks safe — our inference, not a vendor statement

Affected range stops below 20.2R3-S2, so it looks safe — our inference, not a vendor statement

Affected range stops below 20.3R3-S1, so it looks safe — our inference, not a vendor statement

Affected range stops below 20.4R3, so it looks safe — our inference, not a vendor statement

Affected range stops below 21.1R2-S2, 21.1R3, so it looks safe — our inference, not a vendor statement

Affected range stops below 21.2R2, so it looks safe — our inference, not a vendor statement

Junos OS Evolved · Juniper Networks

60%

v < 20.4R3-S2-EVO21.1R1-EVO ≤ v < 21.1*21.2 ≤ v < 21.2R2-EVO21.1R1-EVO 21.2

Affected range stops below 20.4R3-S2-EVO, so it looks safe — our inference, not a vendor statement

Affected range stops below 21.1*, so it looks safe — our inference, not a vendor statement

Affected range stops below 21.2R2-EVO, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

https://kb.juniper.net/JSA11278

References (1)

x_refsource_CONFIRMVendor Advisory

Source: [email protected]

https://kb.juniper.net/JSA11278

CVSS

6.5MEDIUMjuniper

Attack Vector: ADJACENT_NETWORK
Complexity: LOW
Privileges: NONE
User Interaction: NONE
Scope: UNCHANGED
Confidentiality: NONE
Integrity: NONE
Availability: HIGH

Vector?

Quick Info

StatusMODIFIED

CWE

CWE-401

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