CVE-2024-39557

Junos OS Evolved: MAC table changes cause a memory leak

MEDIUM
6.5
CVSS Score
Published: July 10, 2024 at 10:39 PM UTC
Updated: June 17, 2026 at 07:42 AM UTC
2 products affected across 2 vendorsJunos OS EvolvedJunos OS Evolved

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Severity
MEDIUM6.5
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

An Uncontrolled Resource Consumption vulnerability in the Layer 2 Address Learning Daemon (l2ald) of Juniper Networks Junos OS Evolved allows an unauthenticated, adjacent attacker to cause a memory leak, eventually exhausting all system memory, leading to a system crash and Denial of Service (DoS). Certain MAC table updates cause a small amount of memory to leak.  Once memory utilization reaches its limit, the issue will result in a system crash and restart. To identify the issue, execute the CLI command: user@device> show platform application-info allocations app l2ald-agent EVL Object Allocation Statistics: Node   Application     Context Name                               Live   Allocs   Fails     Guids re0   l2ald-agent               net::juniper::rtnh::L2Rtinfo       1069096 1069302   0         1069302 re0   l2ald-agent               net::juniper::rtnh::NHOpaqueTlv     114     195       0         195 This issue affects Junos OS Evolved: * All versions before 21.4R3-S8-EVO, * from 22.2-EVO before 22.2R3-S4-EVO, * from 22.3-EVO before 22.3R3-S3-EVO, * from 22.4-EVO before 22.4R3-EVO, * from 23.2-EVO before 23.2R2-EVO.

Affected

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

v < 21.4R3-S8-EVO22.2-EVO ≤ v < 22.2R3-S4-EVO22.3-EVO ≤ v < 22.3R3-S3-EVO22.4-EVO ≤ v < 22.4R3-EVO23.2-EVO ≤ v < 23.2R2-EVO22.2-EVO22.3-EVO22.4-EVO23.2-EVO
Affected range stops below 21.4R3-S8-EVO, so it looks safe — our inference, not a vendor statement
Affected range stops below 22.2R3-S4-EVO, so it looks safe — our inference, not a vendor statement
Affected range stops below 22.3R3-S3-EVO, so it looks safe — our inference, not a vendor statement
Affected range stops below 22.4R3-EVO, so it looks safe — our inference, not a vendor statement
Affected range stops below 23.2R2-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

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

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

StatusANALYZED
CWE
CWE-400NVD-CWE-noinfo

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