JunosOperating system · Juniper

CVE-2023-22393

HIGH · 7.5 CVSS v3.1 Published 2023-01-13

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

NVD · unedited

An Improper Check for Unusual or Exceptional Conditions vulnerability in BGP route processing of Juniper Networks Junos OS and Junos OS Evolved allows an attacker to cause Routing Protocol Daemon (RPD) crash by sending a BGP route with invalid next-hop 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 without import policy configured. This issue affects: Juniper Networks Junos OS 21.1 versions prior to 21.1R3-S4; 21.2 versions prior to 21.2R3-S3; 21.3 versions prior to 21.3R3-S2; 21.4 versions prior to 21.4R2-S2, 21.4R3; 22.1 versions prior to 22.1R1-S2, 22.1R2; 22.2 versions prior to 22.2R1-S1, 22.2R2. Juniper Networks Junos OS Evolved 21.4-EVO versions prior to 21.4R2-S2-EVO, 21.4R3-EVO; 22.1-EVO versions prior to 22.1R1-S2-EVO, 22.1R2-EVO; 22.2-EVO versions prior to 22.2R1-S1-EVO, 22.2R2-EVO. This issue does not affect: Juniper Networks Junos OS versions prior to 21.1R1. Juniper Networks Junos OS Evolved versions prior to 21.3R1-EVO.

Technical summary

dbcve analysis · high confidence

A vulnerability in Juniper Junos OS and Junos OS Evolved allows remote attackers to crash the Routing Protocol Daemon (RPD) by sending specially crafted BGP routes with invalid next-hop addresses. The issue stems from improper handling of exceptional conditions during BGP route processing, causing a daemon crash and resulting in denial of service.

MitigationApply a BGP import policy to filter routes with invalid next-hops, or upgrade to the patched versions specified in the advisory.

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:= 21.1= 21.2= 21.3= 21.4= 22.1= 22.2

Junos Os EvolvedOperating system

Affected:= 21.4= 22.1= 22.2

CVSS breakdown

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?

dbcve checks

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

Identify installed Junos OS version

Run 'show version' or 'request system software version' command to retrieve the exact Junos OS version running on the device

Affected if The version matches 21.1, 21.2, 21.3, 21.4, 22.1, or 22.2 for Junos OS or 21.4, 22.1, 22.2 for Junos OS Evolved
Verify BGP is configured and active

Run 'show bgp summary' or 'show configuration protocols bgp' to check if BGP protocol is enabled and peers exist

Affected if BGP is enabled and actively exchanging routes with peers
Check BGP peer exposure

Run 'show bgp neighbor' to review which BGP peers are configured and their origin

Affected if The device accepts BGP connections from untrusted or external peers who could send malicious routes
Inspect BGP import policy configuration

Run 'show configuration protocols bgp group' and look for 'import' policy statements under BGP configuration

Affected if No import policy is configured to validate or filter next-hop addresses in received BGP routes

You are affected if your Junos version is one of the listed versions, BGP is actively running, and you accept BGP routes from peers without filtering invalid next-hop addresses.

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

Remediation

dbcve · scoped

Mitigation available No clean upgrade yet — mitigate in the meantime

Mitigation

Apply a BGP import policy to filter routes with invalid next-hops, or upgrade to the patched versions specified in the advisory.

Recommended fix High confidence

Upgrade to the fixed release for your current branch (e.g., 21.4R3, 22.1R2, or 22.2R2)

1. Identify the current Junos OS or Junos OS Evolved version running on the device using 'show version'
2. Based on your current version, upgrade to one of the fixed releases: For 21.1.x upgrade to 21.1R3-S4 or later; For 21.2.x upgrade to 21.2R3-S3 or later; For 21.3.x upgrade to 21.3R3-S2 or later; For 21.4.x upgrade to 21.4R2-S2, 21.4R3, or later; For 22.1.x upgrade to 22.1R1-S2, 22.1R2, or later; For 22.2.x upgrade to 22.2R1-S1, 22.2R2, or later
3. Download the appropriate upgrade package from the Juniper Networks support portal
4. Upload the Junos upgrade package to the device using 'file copy' or USB
5. Install the upgrade using 'request system software add <package-name>' and reboot the device
6. After reboot, verify the new version with 'show version' and confirm BGP is operational with 'show bgp summary'
7. As an additional safeguard (though upgrading is strongly preferred), you may also configure a BGP import policy to filter routes with invalid next-hops using 'set protocols bgp group <name> import <policy-name>' with appropriate next-hop validation terms

Caveat Standard Junos upgrade considerations apply - review release notes for any changes to BGP behavior or deprecated features

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

Fix this in Junos Scoped from the published advisory

Consultation4.0 h
Implementation4.0 h
Testing4.0 h
Review / QA2.0 h

14.0 hours of engineering $2,480

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Scan for this in your stack

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References

Primary sources

kb.juniper.netVendor Advisory
nvd.nist.govNVD record

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2023-22393 in production — separate from our analysis above.

Notes0 Guidelines

Know something about CVE-2023-22393?

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 existsA vendor remedy is published

Severity 7.5 High

Exploit likelihood EPSS, next 30 days 0.6%

Affects: Junos

Remediation

A high-priority fix

Fix this in Junos 14 hrs · Moderate

Typical engagement from $2,480

Get a fix See the full breakdown ↓

A high-priority vulnerability. Send your environment and a specialist will scope CVE-2023-22393 and return a fixed quote and timeline.

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