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NVD / CVE Program· CNA juniper

CVE-2024-21598: Junos OS and Junos OS Evolved: A malformed BGP tunnel encapsulation attribute will lead to an rpd crash

Noroxi assessment

Priority: Monitor (action score 34/100)

  • 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: 0.57% (FIRST EPSS).
  • 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 Junos OS 20.4R3-S9, 21.2R3-S7, 21.3R3-S5; Juniper Networks Junos OS Evolved 20.4R3-S9-EVO, 21.2R3-S7-EVO, 21.3R3-S5-EVO.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Juniper Networks Junos OS 20.4R3-S9, 21.2R3-S7, 21.3R3-S5; Juniper Networks Junos OS Evolved 20.4R3-S9-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 Validation of Syntactic Correctness of Input vulnerability in the Routing Protocol Daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows a network-based, unauthenticated attacker to cause a Denial of Service (DoS). If a BGP update is received over an established BGP session which contains a tunnel encapsulation attribute with a specifically malformed TLV, rpd will crash and restart. This issue affects Juniper Networks Junos OS: * 20.4 versions 20.4R1 and later versions earlier than 20.4R3-S9; * 21.2 versions earlier than 21.2R3-S7; * 21.3 versions earlier than 21.3R3-S5; * 21.4 versions earlier than 21.4R3-S5; * 22.1 versions earlier than 22.1R3-S4; * 22.2 versions earlier than 22.2R3-S3; * 22.3 versions earlier than 22.3R3-S1; * 22.4 versions earlier than 22.4R3; * 23.2 versions earlier than 23.2R1-S2, 23.2R2; Junos OS Evolved: * 20.4-EVO versions 20.4R1-EVO and later versions earlier than 20.4R3-S9-EVO; * 21.2-EVO versions earlier than 21.2R3-S7-EVO; * 21.3-EVO versions earlier than 21.3R3-S5-EVO; * 21.4-EVO versions earlier than 21.4R3-S5-EVO; * 22.1-EVO versions earlier than 22.1R3-S4-EVO; * 22.2-EVO versions earlier than 22.2R3-S3-EVO; * 22.3-EVO versions earlier than 22.3R3-S1-EVO; * 22.4-EVO versions earlier than 22.4R3-EVO; * 23.2-EVO versions earlier than 23.2R1-S2-EVO, 23.2R2-EVO; This issue does not affect Juniper Networks * Junos OS versions earlier than 20.4R1; * Junos OS Evolved versions earlier than 20.4R1-EVO. This is a related but separate issue than the one described in JSA79095.

HighCVSS 8.7 · v4.0—No exploit Fix available
Published
Apr 12, 2024
Updated
Jun 17, 2026
EPSS
0.5% · 47th percentile

Report tools

JSON

Action score

34

Monitor

Low priority for now.

CVSS
34 / 40 · 8.7 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.5%

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.

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

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

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Follow CVE-2024-21598

When you'll hear from us

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  • when exploit code appears or is weaponized
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  • 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 junos20.4
  • 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 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
  • juniper junos os evolved23.2

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 Junos OS

    • 20.4 and later · before 20.4R3-S9affected · semver
    • 21.2 and later · before 21.2R3-S7affected · semver
    • 21.3 and later · before 21.3R3-S5affected · semver
    • 21.4 and later · before 21.4R3-S5affected · semver
    • 22.1 and later · before 22.1R3-S4affected · semver
    • 22.2 and later · before 22.2R3-S3affected · semver
    • 22.3 and later · before 22.3R3-S1affected · semver
    • 22.4 and later · before 22.4R3affected · semver
    • 23.2 and later · before 23.2R1-S2, 23.2R2affected · semver

  • Juniper Networks Junos OS Evolved

    • 20.4-EVO and later · before 20.4R3-S9-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 23.2R1-S2-EVO, 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-2024-21620Jan 25, 2024 · Junos OS: SRX Series and EX Series: J-Web doesn't sufficiently sanitize input to prevent XSS
    24Monitor
  • ← EarlierCVE-2024-21593Apr 12, 2024 · Junos OS: MX Series with MPC10, MPC11, LC9600, and MX304: A specific MPLS packet will cause a PFE crash
    28Monitor
  • Later →CVE-2024-21605Apr 12, 2024 · Junos OS: SRX 300 Series: Specific link local traffic causes a control plane overload
    28Monitor

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 Junos OS20.4R3-S9Vendor (CNA)
Juniper Networks Junos OS21.2R3-S7Vendor (CNA)
Juniper Networks Junos OS21.3R3-S5Vendor (CNA)
Juniper Networks Junos OS21.4R3-S5Vendor (CNA)
Juniper Networks Junos OS22.1R3-S4Vendor (CNA)
Juniper Networks Junos OS22.2R3-S3Vendor (CNA)
Juniper Networks Junos OS22.3R3-S1Vendor (CNA)
Juniper Networks Junos OS22.4R3Vendor (CNA)
Juniper Networks Junos OS23.2R1-S2, 23.2R2Vendor (CNA)
Juniper Networks Junos OS Evolved20.4R3-S9-EVOVendor (CNA)
Juniper Networks Junos OS Evolved21.2R3-S7-EVOVendor (CNA)
Juniper Networks Junos OS Evolved21.3R3-S5-EVOVendor (CNA)
Juniper Networks Junos OS Evolved21.4R3-S5-EVOVendor (CNA)
Juniper Networks Junos OS Evolved22.1R3-S4-EVOVendor (CNA)
Juniper Networks Junos OS Evolved22.2R3-S3-EVOVendor (CNA)
Juniper Networks Junos OS Evolved22.3R3-S1-EVOVendor (CNA)
Juniper Networks Junos OS Evolved22.4R3-EVOVendor (CNA)
Juniper Networks Junos OS Evolved23.2R1-S2-EVO, 23.2R2-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.

No history yet (it accumulates with the daily EPSS job).

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.

  • Matteo MemelliAmazon for responsibly reporting this vulnerability.finder

Variant candidates

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

  • CVE-2024-3954290 days apartJunos OS and Junos OS Evolved: A malformed CFM packet or specific transit traffic leads to FPC crash
    34Monitor
  • CVE-2024-2159592 days apartJunos OS: EX4100, EX4400, EX4600, QFX5000 Series: A high rate of specific ICMP traffic will cause the PFE to hang
    30Monitor
  • CVE-2024-2161692 days apartJunos OS: MX Series and SRX Series: Processing of a specific SIP packet causes NAT IP allocation to fail
    30Monitor
  • CVE-2023-28985273 days apartSRX Series and MX Series: An FPC core is observed when IDP is enabled on the device and a specific malformed SSL packet is received
    30Monitor
  • CVE-2023-44204183 days apartJunos OS and Junos OS Evolved: The rpd will crash upon receiving a malformed BGP UPDATE message
    26Monitor

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).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

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
Integrity
Availability
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
X

Weakness class (CWE)

CWE-1286 · Improper Validation of Syntactic Correctness of Input

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

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

References

Show all references (1 more)

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

All records