NVD / CVE Program· CNA juniper

CVE-2024-39557: Junos OS Evolved: MAC table changes cause a memory leak

Noroxi assessment

Priority: Monitor (action score 28/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.24% (FIRST EPSS).
Someone on the same network segment can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
Fixed version: Juniper Networks Junos OS Evolved 21.4R3-S8-EVO, 22.2R3-S4-EVO, 22.3R3-S3-EVO.
Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Juniper Networks Junos OS Evolved 21.4R3-S8-EVO, 22.2R3-S4-EVO, 22.3R3-S3-EVO or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

HighCVSS 7.1 · v4.0—No exploit Fix available

BDU:2025-03715

Published: Jul 10, 2024
Updated: Jun 17, 2026
EPSS: 0.2% · 15th percentile
CWE: CWE-400

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 28 / 40 · 7.1 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.2%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · juniper: 6.5; NVD has not scored this yet; the score shown is the CNA’s.

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
juniper	junos os evolved	cpe:2.3:o:juniper:junos_os_evolved

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

juniper junos os evolvedbefore 21.4
juniper junos os evolved21.4
juniper junos os evolved22.2
juniper junos os evolved22.3
juniper junos os evolved22.4
juniper junos os evolved23.2

Versions reported by the vendor

Affected version ranges reported by the assigning authority (juniper). Independent of NVD's CPE analysis and usually ahead of it.

Juniper Networks Junos OS Evolved
- before 21.4R3-S8-EVOaffected · semver
- 22.2-EVO and later · before 22.2R3-S4-EVOaffected · semver
- 22.3-EVO and later · before 22.3R3-S3-EVOaffected · semver
- 22.4-EVO and later · before 22.4R3-EVOaffected · semver
- 23.2-EVO and later · before 23.2R2-EVOaffected · semver

Same product

juniper: all records

Other highest-scoring records for the same primary product.

CVE-2026-21902Junos OS Evolved: PTX Series: A vulnerability allows a unauthenticated, network-based attacker to execute code as root
43Plan
CVE-2026-101990Junos OS and Junos OS Evolved: A BGP peer causes an rpd crash when flow-spec routes are re-advertised
37Monitor
CVE-2026-101986Junos OS and Junos OS Evolved: J-Web permits pre-authentication CGI execution
37Monitor

Published before and after this one in the same product

← EarlierCVE-2024-39512Jul 10, 2024 · Junos OS Evolved: User is not logged out when the console cable is disconnected
28Monitor
← EarlierCVE-2024-39513Jul 10, 2024 · Junos OS Evolved: Execution of a specific CLI command will cause a crash in the AFT manager
27Monitor
Later →CVE-2024-39559Jul 10, 2024 · Junos OS Evolved: Receipt of a specific TCP packet may result in a system crash (vmcore) on dual RE systems with NSR enabled
32Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
Juniper Networks Junos OS Evolved	21.4R3-S8-EVO	Vendor (CNA)
Juniper Networks Junos OS Evolved	22.2R3-S4-EVO	Vendor (CNA)
Juniper Networks Junos OS Evolved	22.3R3-S3-EVO	Vendor (CNA)
Juniper Networks Junos OS Evolved	22.4R3-EVO	Vendor (CNA)
Juniper Networks Junos OS Evolved	23.2R2-EVO	Vendor (CNA)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

CVE-2024-395481 days apartJunos OS Evolved: Receipt of specific packets in the aftmand process will lead to a memory leak
28Monitor
CVE-2025-52961456 days apartJunos OS Evolved: PTX Series except PTX10003: An unauthenticated adjacent attacker sending specific valid traffic can cause a memory leak in cfmman leading to F
28Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

TR-24-0943 · Jul 16, 2024(Juniper Junos OS Güvenlik Bildirimi)

All national notices →

Technical details

Attack conditions

Someone on the same network segment can trigger it.
No account or password is required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability

Attack vector: Adjacent
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: X

Weakness class (CWE)

CWE-400 · Uncontrolled Resource Consumption

CVSS vector

CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:A/V:X/RE:X/U:X

nvd-secondary

Root cause

Code that parses nested structures sets no depth or size limit. A small input can turn into a disproportionate processing load.

The bug in code

The whole CWE-400 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1function expand(node) {
2  return node.children.map(expand);
3}

Fixed

1const MAX_DEPTH = 32;
2function expand(node, depth = 0) {
3  if (depth > MAX_DEPTH) throw new Error("too deep");
4  return node.children.map((c) => expand(c, depth + 1));
5}

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

ATT&CK techniques

Endpoint Denial of ServiceT1499

Change log

Fix✗ → ✓Sep 28, 2026, 10:09 PM UTC

For records you follow, these changes also arrive as notifications. →

References

supportportal.juniper.net/JSA83017

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records