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JunosOperating system · Juniper

CVE-2025-30659

HIGH · 7.5 CVSS v3.1 Published 2025-04-09
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
Remotely reachable 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 Improper Handling of Length Parameter Inconsistency vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on SRX Series allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS). When a device configured for Secure Vector Routing (SVR) receives a specifically malformed packet the PFE will crash and restart. This issue affects Junos OS on SRX Series: * All 21.4 versions, * 22.2 versions before 22.2R3-S6, * 22.4 versions before 22.4R3-S6, * 23.2 versions before 23.2R2-S3, * 23.4 versions before 23.4R2-S4, * 24.2 versions before 24.2R2. This issue does not affect versions before 21.4.

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

A length parameter inconsistency in the Packet Forwarding Engine (PFE) of Juniper Junos OS on SRX Series allows an unauthenticated attacker to send a specifically malformed packet to a device configured for Secure Vector Routing (SVR), triggering a PFE crash and restart causing denial of service.

MitigationApply the vendor-supplied patches by upgrading to the fixed versions (22.2R3-S6, 22.4R3-S6, 23.2R2-S3, 23.4R2-S4, or 24.2R2) or disable SVR if not required while planning the upgrade.

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
JunosOperating system
Affected:= 21.4= 22.2= 22.4= 23.2= 23.4= 24.2

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
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

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

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. Confirm device is SRX Series
    Run 'show chassis hardware' or 'show system information' to identify the device model. Ensure it is an SRX Series firewall.
    Affected if Device is not an SRX Series model - the vulnerability only affects SRX devices
  2. Check Junos OS version
    Run 'show version' or 'show system information' to obtain the installed Junos OS version.
    Affected if Version matches one of the affected releases: 21.4, 22.2, 22.4, 23.2, 23.4, or 24.2
  3. Verify Secure Vector Routing is enabled
    Run 'show configuration routing-options' and look for 'secure-vector-routing' under the routing-options hierarchy, or check 'show configuration' for any SVR-related configuration.
    Affected if SVR is configured and enabled - this is required for the malformed packet to trigger the PFE crash

Device is affected if it is an SRX Series running a listed affected Junos version AND has Secure Vector Routing (SVR) enabled in the configuration.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the vendor-supplied patches by upgrading to the fixed versions (22.2R3-S6, 22.4R3-S6, 23.2R2-S3, 23.4R2-S4, or 24.2R2) or disable SVR if not required while planning the upgrade.

Recommended fix High confidence

24.2R2 (or later stable release)

  1. Identify the current Junos OS version running on the SRX Series device using 'show version'
  2. Confirm the device is configured for Secure Vector Routing (SVR) if possible using 'show configuration | match svr'
  3. Schedule a maintenance window for the upgrade to minimize disruption
  4. Download the appropriate fixed Junos OS image (22.2R3-S6, 22.4R3-S6, 23.2R2-S3, 23.4R2-S4, or 24.2R2 or later) from Juniper Networks
  5. Upload the new Junos OS image to the device using 'request system software add' or similar method
  6. Reboot the device to apply the new software using 'request system reboot'
  7. After reboot, verify the PFE is operational using 'show chassis fabric fpc' and confirm normal device operation
Caveat Standard Junos OS upgrade considerations apply - review release notes for any configuration changes or compatibility notes before upgrading

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

Fix this in Junos Scoped from the published advisory
  • Consultation4.0 h
  • Implementation3.0 h
  • Testing4.0 h
  • Review / QA2.0 h
13.0 hours of engineering $2,300
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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-2025-30659 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data