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JunosOperating system · Juniper

CVE-2025-21600

MEDIUM · 6.5 CVSS v3.1 Published 2025-01-09
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
70/100
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 Out-of-Bounds Read vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, logically adjacent BGP peer sending a specifically malformed BGP packet to cause rpd to crash and restart, resulting in a Denial of Service (DoS). Continued receipt and processing of this packet will create a sustained Denial of Service (DoS) condition. This issue only affects systems configured in either of two ways: * systems with BGP traceoptions enabled * systems with BGP family traffic-engineering (BGP-LS) configured and can be exploited from a directly connected and configured BGP peer.  This issue affects iBGP and eBGP with any address family configured, and both IPv4 and IPv6 are affected by this vulnerability. This issue affects: Junos OS:  * from 21.4 before 21.4R3-S9,  * from 22.2 before 22.2R3-S5,  * from 22.3 before 22.3R3-S4,  * from 22.4 before 22.4R3-S5,  * from 23.2 before 23.2R2-S3,  * from 23.4 before 23.4R2-S3,  * from 24.2 before 24.2R1-S2, 24.2R2;  Junos OS Evolved:  * from 21.4-EVO before 21.4R3-S9-EVO,  * from 22.2-EVO before 22.2R3-S5-EVO,  * from 22.3-EVO before 22.3R3-S4-EVO,  * from 22.4-EVO before 22.4R3-S5-EVO,  * from 23.2-EVO before 23.2R2-S3-EVO,  * from 23.4-EVO before 23.4R2-S2-EVO,  * from 24.2-EVO before 24.2R1-S2-EVO, 24.2R2-EVO. This issue does not affect versions of Junos OS prior to 21.3R1. This issue does not affect versions of Junos OS Evolved prior to 21.3R1-EVO. This is a similar, but different vulnerability than the issue reported as CVE-2024-39516.

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

An out-of-bounds read vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, logically adjacent BGP peer to send a specifically malformed BGP packet that causes rpd to crash and restart, resulting in denial of service. The vulnerability only affects systems with BGP traceoptions enabled or BGP-LS (traffic-engineering) configured.

MitigationApply vendor-supplied patches to reach the fixed versions (21.4R3-S9, 22.2R3-S5, 22.3R3-S4, 22.4R3-S5, 23.2R2-S3, 23.4R2-S3, 24.2R1-S2 or later). Alternatively, if patch deployment is not immediately feasible, disable BGP traceoptions or BGP-LS configuration if not operationally required, as these are the preconditions for exploitation.

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= 22.3= 22.4= 23.2= 23.4= 24.2
Junos Os EvolvedOperating system
Affected:= 21.4= 22.2= 22.3= 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
Adjacent
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:A/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. Check the Junos OS version
    Run 'show version' or 'show version detail' to obtain the installed Junos version. Compare against affected versions: 21.4, 22.2, 22.3, 22.4, 23.2, 23.4, and 24.2.
    Affected if The installed version matches one of the affected versions listed.
  2. Verify if BGP traceoptions is enabled
    Run 'show configuration protocols bgp | display set' or examine the configuration for any 'traceoptions' stanza under the BGP protocol configuration.
    Affected if BGP traceoptions are configured and enabled in the device configuration.
  3. Verify if BGP-LS is configured
    Run 'show configuration protocols bgp' and look for 'traffic-engineering' or 'address-family link-state' under the BGP configuration hierarchy.
    Affected if BGP-LS (link-state or traffic-engineering address family) is configured under BGP.

A system is affected if it runs an affected Junos version AND has either BGP traceoptions enabled or BGP-LS configured; otherwise the vulnerability cannot be exploited.

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 vendor-supplied patches to reach the fixed versions (21.4R3-S9, 22.2R3-S5, 22.3R3-S4, 22.4R3-S5, 23.2R2-S3, 23.4R2-S3, 24.2R1-S2 or later). Alternatively, if patch deployment is not immediately feasible, disable BGP traceoptions or BGP-LS configuration if not operationally required, as these are the preconditions for exploitation.

Recommended fix High confidence

Junos OS: 21.4R3-S9, 22.2R3-S5, 22.3R3-S4, 22.4R3-S5, 23.2R2-S3, 23.4R2-S3, 24.2R1-S2, or 24.2R2 | Junos OS Evolved: 21.4R3-S9-EVO, 22.2R3-S5-EVO, 22.3R3-S4-EVO, 22.4R3-S5-EVO, 23.2R2-S3-EVO, 23.4R2-S2-EVO, 24.2R1-S2-EVO, or 24.2R2-EVO

  1. Identify the currently installed Junos OS or Junos OS Evolved version using `show version`
  2. Determine the appropriate upgrade path based on the current version branch
  3. For Junos OS: upgrade to 21.4R3-S9 or later, 22.2R3-S5 or later, 22.3R3-S4 or later, 22.4R3-S5 or later, 23.2R2-S3 or later, 23.4R2-S3 or later, or 24.2R1-S2/24.2R2 or later
  4. For Junos OS Evolved: upgrade to 21.4R3-S9-EVO or later, 22.2R3-S5-EVO or later, 22.3R3-S4-EVO or later, 22.4R3-S5-EVO or later, 23.2R2-S3-EVO or later, 23.4R2-S2-EVO or later, or 24.2R1-S2-EVO/24.2R2-EVO or later
  5. Download the appropriate upgrade image from the Juniper Networks support portal
  6. Perform the upgrade following standard Junos upgrade procedures, ensuring to backup the configuration
  7. After upgrade, verify the rpd process is running and BGP peering is established using `show bgp summary`
Caveat Standard Junos upgrade considerations apply - review release notes for any configuration changes between versions

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

Fix this in Junos Scoped from the published advisory
  • Consultation3.0 h
  • Implementation3.0 h
  • Testing2.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,800
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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-2025-21600 in production — separate from our analysis above.

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What this is

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  • Version or environment caveats, and links to real fixes
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