CVE-2024-21590

Sustained service interruption via misrouted MPLS packets

Published Apr 12, 2024 · Updated Aug 1, 2024

Improper input validation in Junos OS Evolved allows remote attackers within an MPLS domain to sustain a service interruption. The Juniper Tunnel Driver and ICMP module forward crafted transit MPLS IPv4 packets from the PFE to the Routing Engine even though they are not destined for the device. Reachability requires a position inside the MPLS administrative domain, and continued packet delivery sustains the service interruption.

CVSS severity7.1
High
EPSS probability0.36%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in Junos OS Evolved allows remote attackers within an MPLS domain to sustain a service interruption. The Juniper Tunnel Driver and ICMP module forward crafted transit MPLS IPv4 packets from the PFE to the Routing Engine even though they are not destined for the device. Reachability requires a position inside the MPLS administrative domain, and continued packet delivery sustains the service interruption.

The record

CVE
CVE-2024-21590
Published
Apr 12, 2024
Updated
Aug 1, 2024
Vendor
Juniper Networks
Product
Junos OS Evolved
Classifications
CWE-20, T1498
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 12, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 1, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <21.2R3-S8-EVO
  2. Affected versionversion=21.4-EVO <21.4R3-S6-EVO
  3. Affected versionversion=22.2-EVO <22.2R3-S4-EVO
  4. Affected versionversion=22.3-EVO <22.3R3-S3-EVO
  5. Affected versionversion=22.4-EVO <22.4R3-EVO
  6. Affected versionversion=23.2-EVO <23.2R2-EVO
  7. Affected versionversion=23.4-EVO <23.4R1-S1-EVO

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Juniper Networks · Junos OS Evolvedversion=0 <21.2R3-S8-EVO; version=21.4-EVO <21.4R3-S6-EVO; version=22.2-EVO <22.2R3-S4-EVO; version=22.3-EVO <22.3R3-S3-EVO; version=22.4-EVO <22.4R3-EVO; version=23.2-EVO <23.2R2-EVO; version=23.4-EVO <23.4R1-S1-EVO

Published CVSS scores

5.3Juniper NetworksCVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
7.1Juniper NetworksCVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation
T1498Network Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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