CVE-2024-39555Network attack vector

Sustained BGP session resets via malformed tunnel attribute

Published Jul 10, 2024 · Updated Aug 2, 2024

Improper exception handling in the RPD of Junos OS and Junos OS Evolved allows remote attackers to reset BGP sessions. RPD improperly parses attributes following a malformed tunnel encapsulation attribute and sends an invalid-attribute-list notification. Reachability requires segment routing and an established IPv4 or IPv6 eBGP or iBGP session; repeated updates sustain the service interruption.

CVSS severity8.7
High
EPSS probability0.50%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper exception handling in the RPD of Junos OS and Junos OS Evolved allows remote attackers to reset BGP sessions. RPD improperly parses attributes following a malformed tunnel encapsulation attribute and sends an invalid-attribute-list notification. Reachability requires segment routing and an established IPv4 or IPv6 eBGP or iBGP session; repeated updates sustain the service interruption.

The record

CVE
CVE-2024-39555
Published
Jul 10, 2024
Updated
Aug 2, 2024
Vendor
Juniper Networks
Product
Junos OS Evolved
Classifications
CWE-755, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 10, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 2, 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 <21.4R3-S8-EVO
  2. Affected versionversion=22.2-EVO <22.2R3-S4-EVO
  3. Affected versionversion=22.3-EVO <22.3R3-S3-EVO
  4. Affected versionversion=22.4-EVO <22.4R3-S3-EVO
  5. Affected versionversion=23.2-EVO <23.2R2-S1-EVO
  6. Affected versionversion=23.4-EVO <23.4R1-S2-EVO
  7. Affected versionversion=23.4-EVO <23.4R1-S2-EVO, 23.4R2-EVO
  8. Affected versionversion=23.4-EVO <23.4R2-EVO

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Juniper Networks · Junos OS Evolvedversion=0 <21.4R3-S8-EVO; version=22.2-EVO <22.2R3-S4-EVO; version=22.3-EVO <22.3R3-S3-EVO; version=22.4-EVO <22.4R3-S3-EVO; version=23.2-EVO <23.2R2-S1-EVO; version=23.4-EVO <23.4R1-S2-EVO; version=23.4-EVO <23.4R1-S2-EVO, 23.4R2-EVO; version=23.4-EVO <23.4R2-EVO
Juniper Networks · Junos OSversion=0 <21.4R3-S8; version=22.2 <22.2R3-S4; version=22.3 <22.3R3-S3; version=22.4 <22.4R3-S3; version=23.2 <23.2R2-S1; version=23.4 <23.4R1-S2; version=23.4 <23.4R1-S2, 23.4R2; version=23.4 <23.4R2

Published CVSS scores

8.7Juniper Networks, Inc.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/R:A
7.5Juniper Networks, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-755Improper Handling of Exceptional Conditions
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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