dbcve.org
Junos Os EvolvedOperating system · Juniper

CVE-2024-39534

MEDIUM · 5.4 CVSS v3.1 Published 2024-10-11
Fix available
A fix is available. Upgrade to 21.4 or later.
See remediation →
59/100
Remediation priority · Elevated
No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
An Incorrect Comparison vulnerability in the local address verification API of Juniper Networks Junos OS Evolved allows an unauthenticated network-adjacent attacker to create sessions or send traffic to the device using the network and broadcast address of the subnet assigned to an interface. This is unintended and unexpected behavior and can allow an attacker to bypass certain compensating controls, such as stateless firewall filters. This issue affects Junos OS Evolved:  * All versions before 21.4R3-S8-EVO,  * 22.2-EVO before 22.2R3-S4-EVO,  * 22.3-EVO before 22.3R3-S4-EVO,  * 22.4-EVO before 22.4R3-S3-EVO,  * 23.2-EVO before 23.2R2-S1-EVO,  * 23.4-EVO before 23.4R1-S2-EVO, 23.4R2-EVO.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

The vulnerability is an incorrect comparison flaw in Junos OS Evolved's local address verification API. This allows unauthenticated network-adjacent attackers to send traffic or create sessions using the network and broadcast addresses of a subnet assigned to an interface, which should normally be rejected. This bypasses compensating controls like stateless firewall filters that rely on proper address validation.

MitigationApply the appropriate Junos OS Evolved patch per the version matrix (21.4R3-S8-EVO, 22.2R3-S4-EVO, 22.3R3-S4-EVO, 22.4R3-S3-EVO, 23.2R2-S1-EVO, 23.4R1-S2-EVO or later). Review existing firewall filter configurations as a compensating control until patching is complete.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Junos Os EvolvedOperating system
Affected:< 21.4= 21.4= 22.2= 22.3= 22.4= 23.2= 23.4

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Adjacent
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
None

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Determine the Junos OS Evolved version
    Run the command 'show version' or 'show version detail' on the device to obtain the installed software version
    Affected if The installed version is < 21.4, = 21.4, = 22.2, = 22.3, = 22.4, = 23.2, or = 23.4
  2. Identify interfaces with assigned subnets
    Run 'show configuration interfaces' and review interface unit configurations for addresses assigned in the format 'x.x.x.x/nn'
    Affected if Any interface has a subnet assigned; the vulnerability affects traffic sent to network and broadcast addresses of these subnets
  3. Verify local address verification behavior
    Attempt to ping or send traffic to the network address and broadcast address of a configured subnet from a network-adjacent host
    Affected if Traffic to network or broadcast addresses is accepted when it should be rejected (this indicates the flaw is present)
  4. Review firewall filter configurations
    Run 'show configuration firewall' and inspect any stateless filters applied to interfaces
    Affected if Firewall filters exist as compensating controls, but the vulnerability may still allow traffic that should be blocked based on improper address validation

The device is affected if it runs Junos OS Evolved version 21.4, 22.2, 22.3, 22.4, 23.2, or 23.4 (or any version below 21.4) and has network interfaces with assigned subnets, because the local address verification flaw allows network and broadcast addresses to be used when they should be rejected.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 21.4 or later
Fixed in 21.4
Interim mitigation

Apply the appropriate Junos OS Evolved patch per the version matrix (21.4R3-S8-EVO, 22.2R3-S4-EVO, 22.3R3-S4-EVO, 22.4R3-S3-EVO, 23.2R2-S1-EVO, 23.4R1-S2-EVO or later). Review existing firewall filter configurations as a compensating control until patching is complete.

Recommended fix High confidence

21.4R3-S8-EVO, 22.2R3-S4-EVO, 22.3R3-S4-EVO, 22.4R3-S3-EVO, 23.2R2-S1-EVO, or 23.4R1-S2-EVO (choose the appropriate branch for your current version)

  1. 1. Identify the current Junos OS Evolved version running on the device using 'show version' command
  2. 2. Determine the appropriate fixed release based on the current version branch (21.4, 22.2, 22.3, 22.4, 23.2, or 23.4)
  3. 3. Download the corresponding fixed software image from the Juniper Networks support portal
  4. 4. Transfer the software image to the device using SCP or USB
  5. 5. Install the software upgrade using the 'request system software add <image-name>' command
  6. 6. Reboot the device using 'request system reboot' command to apply the new software
  7. 7. After reboot, verify the fix is applied by checking the version and confirming the patch level (e.g., 21.4R3-S8-EVO or higher)
Caveat Standard Junos upgrade precautions apply - review Junos OS Evolved upgrade documentation, ensure backup configurations, and plan maintenance window as upgrades may cause service interruption

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Junos Os Evolved Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing12.0 h
  • Review / QA4.0 h
28.0 hours of engineering $4,760
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2024-39534 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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