JunosOperating system · Juniper

CVE-2025-52953

MEDIUM · 6.5 CVSS v3.1 Published 2025-07-11

Fix available

A fix is available. Upgrade to 21.2 / 22.2 or later.

See remediation →

70/100

Remediation priority · Elevated

No privileges Zero-click

Official description

NVD · unedited

An Expected Behavior Violation vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated adjacent attacker sending a valid BGP UPDATE packet to cause a BGP session reset, resulting in a Denial of Service (DoS). Continuous receipt and processing of this packet will create a sustained Denial of Service (DoS) condition. This issue affects iBGP and eBGP and both IPv4 and IPv6 are affected by this vulnerability. This issue affects Junos OS: * All versions before 21.2R3-S9, * from 21.4 before 21.4R3-S11, * from 22.2 before 22.2R3-S7, * from 22.4 before 22.4R3-S7, * from 23.2 before 23.2R2-S4, * from 23.4 before 23.4R2-S4, * from 24.2 before 24.2R2, * from 24.4 before 24.4R1-S3, 24.4R2 Junos OS Evolved: * All versions before 22.2R3-S7-EVO, * from 22.4-EVO before 22.4R3-S7-EVO, * from 23.2-EVO before 23.2R2-S4-EVO, * from 23.4-EVO before 23.4R2-S4-EVO, * from 24.2-EVO before 24.2R2-EVO, * from 24.4-EVO before 24.4R1-S3-EVO, 24.4R2-EVO.

Technical summary

dbcve analysis · high confidence

A vulnerability in Juniper's routing protocol daemon (rpd) allows an unauthenticated adjacent attacker sending a valid but specially crafted BGP UPDATE packet to trigger unexpected behavior, causing the BGP session to reset. Continuous receipt of these packets creates a sustained Denial of Service condition affecting both iBGP and eBGP across IPv4 and IPv6.

MitigationApply the appropriate Junos OS or Junos OS Evolved software update from Juniper Networks to patch the vulnerability; as interim mitigation, consider implementing BGP session rate limiting or prefix filtering to reduce attack surface.

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

Affected products & versions

NVD · CPE data

JunosOperating system

Affected:< 21.2= 21.2= 21.4= 22.2= 22.4= 23.2= 23.4= 24.2= 24.4

Junos Os EvolvedOperating system

Affected:< 22.2= 22.2= 22.4= 23.2= 23.4= 24.2= 24.4

CVSS breakdown

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?

dbcve checks

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

Identify the Junos version

Run 'show version' or 'show version detail' on the Juniper device to retrieve the installed Junos OS or Junos OS Evolved version

Affected if The displayed version matches any of these: Junos < 21.2, = 21.2, = 21.4, = 22.2, = 22.4, = 23.2, = 23.4, = 24.2, = 24.4; or Junos OS Evolved < 22.2, = 22.2, = 22.4, = 23.2, = 23.4, = 24.2, = 24.4
Verify BGP is configured

Run 'show configuration protocols bgp' to see if BGP protocol is configured on the device

Affected if BGP is configured and the device participates in BGP routing
Check BGP peer exposure

Run 'show bgp summary' and 'show configuration protocols bgp group' to identify BGP peer addresses and groups, then determine if any peers are accessible from adjacent or untrusted network segments

Affected if BGP peers are reachable from network segments accessible to adjacent attackers (e.g., external-facing interfaces, shared LAN segments)
Review BGP session stability

Run 'show bgp summary' and check for any recently reset sessions or check system logs (show log messages) for BGP reset events around the time of potential attacks

Affected if BGP sessions are resetting without apparent legitimate cause or configuration changes

The device is affected if it runs a vulnerable Junos version, has BGP enabled, and BGP peers are reachable from adjacent network segments where an attacker could send crafted BGP UPDATE packets.

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

Remediation

dbcve · scoped

Upgrade available Upgrade to 21.2 / 22.2 or later

Fixed in 21.222.2

Interim mitigation

Apply the appropriate Junos OS or Junos OS Evolved software update from Juniper Networks to patch the vulnerability; as interim mitigation, consider implementing BGP session rate limiting or prefix filtering to reduce attack surface.

Recommended fix High confidence

Junos OS: 21.2R3-S9, 21.4R3-S11, 22.2R3-S7, 22.4R3-S7, 23.2R2-S4, 23.4R2-S4, 24.2R2, or 24.4R1-S3/24.4R2 (depending on your current branch); Junos OS Evolved: 22.2R3-S7-EVO, 22.4R3-S7-EVO, 23.2R2-S4-EVO, 23.4R2-S4-EVO, 24.2R2-EVO, or 24.4R1-S3-EVO/24.4R2-EVO (depending on your current branch)

Identify the current Junos OS or Junos OS Evolved version running on the device using 'show version'
Determine which branch of Junos you are currently running (21.2, 21.4, 22.2, 22.4, 23.2, 23.4, 24.2, or 24.4)
For Junos OS: Upgrade to the minimum fixed version for your branch: 21.2R3-S9, 21.4R3-S11, 22.2R3-S7, 22.4R3-S7, 23.2R2-S4, 23.4R2-S4, 24.2R2, or 24.4R1-S3/24.4R2
For Junos OS Evolved: Upgrade to the minimum fixed version for your branch: 22.2R3-S7-EVO, 22.4R3-S7-EVO, 23.2R2-S4-EVO, 23.4R2-S4-EVO, 24.2R2-EVO, or 24.4R1-S3-EVO/24.4R2-EVO
Download the appropriate upgrade image from Juniper Networks support portal
Perform the upgrade following standard Junos upgrade procedures, typically using 'request system software add' command
After upgrade, verify the new version is running with 'show version'
Verify BGP peering is established and stable with 'show bgp summary'

Caveat Standard Junos upgrade precautions apply - review Junos upgrade guide, ensure compatibility with other network devices, and schedule maintenance window as upgrade will cause BGP session disruption

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

Fix this in Junos Scoped from the published advisory

Consultation4.0 h
Implementation8.0 h
Testing6.0 h
Review / QA2.0 h

20.0 hours of engineering $3,500

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References

Primary sources

supportportal.juniper.netVendor Advisory
www.juniper.netTechnical Description
nvd.nist.govNVD record

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-52953 in production — separate from our analysis above.

Notes0 Guidelines

Know something about CVE-2025-52953?

The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.

The version that genuinely resolved it — not the one the vendor claimed
A config change or rule that shut the vector down
A gotcha in the upgrade path that cost you an afternoon

No notes yet

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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

At a glance

A fix existsUpgrade to 21.2 / 22.2 or later

Severity 6.5 Medium

Exploit likelihood EPSS, next 30 days 0.3%

Affects: Junos

Remediation

Need this fixed?

Fix this in Junos 20 hrs · Moderate

Typical engagement from $3,500

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You’ll deal with our team directly and deploy the reviewed fix to staging first — never straight to production.

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.

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.

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.

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.

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.

Check your environment

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.

Scan for this in your stack

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Practitioner notes

No notes yet

Official description

Technical summary

Affected products & versions

CVSS breakdown

Am I affected?

Remediation

References