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NVD / CVE Program· CNA juniper

CVE-2023-4481: Junos OS and Junos OS Evolved: A crafted BGP UPDATE message allows a remote attacker to de-peer (reset) BGP sessions (CVE-2023-4481)

Noroxi assessment

Priority: Monitor (action score 36/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 18.3% (FIRST EPSS); higher than 97.2% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: Juniper Networks, Inc. Junos OS 20.4R3-S10, 21.2R3-S5, 21.3R3-S5; Juniper Networks, Inc. Junos OS Evolved 20.4R3-S10-EVO, 21.2R3-S7-EVO, 21.3R3-S5-EVO.

Low priority for now. Upgrade to Juniper Networks, Inc. Junos OS 20.4R3-S10, 21.2R3-S5, 21.3R3-S5; Juniper Networks, Inc. Junos OS Evolved 20.4R3-S10-EVO, 21.2R3-S7-EVO, 21.3R3-S5-EVO or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

An Improper Input Validation vulnerability in the Routing Protocol Daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, network-based attacker to cause a Denial of Service (DoS). When certain specific crafted BGP UPDATE messages are received over an established BGP session, one BGP session may be torn down with an UPDATE message error, or the issue may propagate beyond the local system which will remain non-impacted, but may affect one or more remote systems. This issue is exploitable remotely as the crafted UPDATE message can propagate through unaffected systems and intermediate BGP speakers. Continuous receipt of the crafted BGP UPDATE messages will create a sustained Denial of Service (DoS) condition for impacted devices. This issue affects eBGP and iBGP, in both IPv4 and IPv6 implementations. This issue requires a remote attacker to have at least one established BGP session. Improper Input Validation, Denial of Service vulnerability in Juniper Networks, Inc. Junos OS (BGP, rpd modules), Juniper Networks, Inc. Junos OS Evolved (BGP, rpd modules) allows Fuzzing.This issue affects  Junos OS:  * All versions before 20.4R3-S10, * from 21.1R1 through 21.*, * from 21.2 before 21.2R3-S5, * from 21.3 before 21.3R3-S5, * from 21.4 before 21.4R3-S7 (unaffected from 21.4R3-S5, affected from 21.4R3-S6) * from 22.1 before 22.1R3-S4, * from 22.2 before 22.2R3-S3, * from 22.3 before 22.3R3-S1, * from 22.4 before 22.4R3, * from 23.2 before 23.2R2. Junos OS Evolved: * All versions before 20.4R3-S10-EVO, * from 21.2-EVO before 21.2R3-S7-EVO, * from 21.3-EVO before 21.3R3-S5-EVO, * from 21.4-EVO before 21.4R3-S5-EVO, * from 22.1-EVO before 22.1R3-S4-EVO, * from 22.2-EVO before 22.2R3-S3-EVO, * from 22.3-EVO before 22.3R3-S1-EVO, * from 22.4-EVO before 22.4R3-EVO, * from 23.2-EVO before 23.2R2-EVO.

HighCVSS 7.5 · v3.1—No exploit Fix available
Published
Aug 31, 2023
Updated
Jun 17, 2026
EPSS
18.3% · 97th percentile

Report tools

JSON

Action score

36

Monitor

Low priority for now.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
6 / 30 · 18.3%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · juniper
7.5
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2023-4481

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
juniperjunos
juniperjunos os evolved

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • juniper junosbefore 20.4
  • juniper junos20.4
  • juniper junos21.1
  • juniper junos21.2
  • juniper junos21.3
  • juniper junos21.4
  • juniper junos22.1
  • juniper junos22.2
  • juniper junos22.3
  • juniper junos22.4
  • juniper junos23.2
  • juniper junos os evolvedbefore 20.4
  • juniper junos os evolved20.4
  • juniper junos os evolved21.2
  • juniper junos os evolved21.3
  • juniper junos os evolved21.4
  • juniper junos os evolved22.1
  • juniper junos os evolved22.2
  • juniper junos os evolved22.3
  • juniper junos os evolved22.4

Versions reported by the vendor

Affected version ranges reported by the assigning authority (juniper). Independent of NVD's CPE analysis and usually ahead of it.

  • Juniper Networks, Inc. Junos OS

    • before 20.4R3-S10affected · semver
    • 21.2 and later · before 21.2R3-S5affected · semver
    • 21.3 and later · before 21.3R3-S5affected · semver
    • 21.4 and later · before 21.4R3-S7affected · semverfixed in 21.4R3-S5
    • 22.1 and later · before 22.1R3-S4affected · semver
    • 22.2 and later · before 22.2R3-S3affected · se
    • 22.3 and later · before 22.3R3-S1affected · semver
    • 22.4 and later · before 22.4R3affected · semver
    • 23.2 and later · before 23.2R2affected · semver
    • 21.1R1 and later · up to and including 21.*affected · semver

  • Juniper Networks, Inc. Junos OS Evolved

    • before 20.4R3-S10-EVOaffected · semver
    • 21.2-EVO and later · before 21.2R3-S7-EVOaffected · semver
    • 21.3-EVO and later · before 21.3R3-S5-EVOaffected · semver
    • 21.4-EVO and later · before 21.4R3-S5-EVOaffected · semver
    • 22.1-EVO and later · before 22.1R3-S4-EVOaffected · semver
    • 22.2-EVO and later · before 22.2R3-S3-EVOaffected · semver
    • 22.3-EVO and later · before 22.3R3-S1-EVOaffected · semver
    • 22.4-EVO and later · before 22.4R3-EVOaffected · semver
    • 23.2-EVO and later · before 23.2R2-EVOaffected · semver

Same product

juniper: all records

Other highest-scoring records for the same primary product.

  • CVE-2023-36845Junos OS: EX and SRX Series: A PHP vulnerability in J-Web allows an unauthenticated to control an important environment variableKEV
    98Now
  • CVE-2023-36846Junos OS: SRX Series: A vulnerability in J-Web allows an unauthenticated attacker to upload arbitrary filesKEV
    79This week
  • CVE-2023-36844Junos OS: EX Series: A PHP vulnerability in J-Web allows an unauthenticated attacker to control important environment variablesKEV
    78This week

Published before and after this one in the same product

  • ← EarlierCVE-2023-36850Jul 14, 2023 · Junos OS: MX Series: An MPC will crash upon receipt of a malformed CFM packet.
    26Monitor
  • ← EarlierCVE-2023-36847Aug 17, 2023 · Junos OS: EX Series: A vulnerability in J-Web allows an unauthenticated attacker to upload arbitrary filesKEV
    76This week
  • Later →CVE-2023-36851Sep 27, 2023 · Junos OS: SRX Series: A vulnerability in J-Web allows an unauthenticated attacker to upload and download arbitrary filesKEV
    60This week

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Juniper Networks, Inc. Junos OS20.4R3-S10Vendor (CNA)
Juniper Networks, Inc. Junos OS21.2R3-S5Vendor (CNA)
Juniper Networks, Inc. Junos OS21.3R3-S5Vendor (CNA)
Juniper Networks, Inc. Junos OS21.4R3-S5Vendor (CNA)
Juniper Networks, Inc. Junos OS21.4R3-S7Vendor (CNA)
Juniper Networks, Inc. Junos OS22.1R3-S4Vendor (CNA)
Juniper Networks, Inc. Junos OS22.2R3-S3Vendor (CNA)
Juniper Networks, Inc. Junos OS22.3R3-S1Vendor (CNA)
Juniper Networks, Inc. Junos OS22.4R3Vendor (CNA)
Juniper Networks, Inc. Junos OS23.2R2Vendor (CNA)
Juniper Networks, Inc. Junos OS Evolved20.4R3-S10-EVOVendor (CNA)
Juniper Networks, Inc. Junos OS Evolved21.2R3-S7-EVOVendor (CNA)
Juniper Networks, Inc. Junos OS Evolved21.3R3-S5-EVOVendor (CNA)
Juniper Networks, Inc. Junos OS Evolved21.4R3-S5-EVOVendor (CNA)
Juniper Networks, Inc. Junos OS Evolved22.1R3-S4-EVOVendor (CNA)
Juniper Networks, Inc. Junos OS Evolved22.2R3-S3-EVOVendor (CNA)
Juniper Networks, Inc. Junos OS Evolved22.3R3-S1-EVOVendor (CNA)
Juniper Networks, Inc. Junos OS Evolved22.4R3-EVOVendor (CNA)
Juniper Networks, Inc. Junos OS Evolved23.2R2-EVOVendor (CNA)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-20 · Improper Input Validation

CVSS vector

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

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (3 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records