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Fencer Vulns
high 7.5

CVE-2024-39552 json

Junos OS and Junos OS Evolved: Malformed BGP UPDATE causes RPD crash

published 2024-07-11 2 y ago modified 2026-06-17 4 mo ago also EUVD-2024-38078

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 48%
public exploits
0
none known

Summary

An Improper Handling of Exceptional Conditions vulnerability in the routing protocol daemon (RPD) of Juniper Networks Junos OS and Junos OS Evolved allows a network based, unauthenticated attacker to cause the RPD process to crash leading to a Denial of Service (DoS).

When a malformed BGP UPDATE packet is received over an established BGP session, RPD crashes and restarts.

Continuous receipt of the malformed 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.

This issue affects:

Juniper Networks Junos OS: * All 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-S6; * 22.1 versions earlier than 22.1R3-S4; * 22.2 versions earlier than 22.2R3-S3; * 22.3 versions earlier than 22.3R3-S2; * 22.4 versions earlier than 22.4R3; * 23.2 versions earlier than 23.2R2.

Juniper Networks Junos OS Evolved: * All versions earlier than 21.2R3-S7; * 21.3-EVO versions earlier than 21.3R3-S5; * 21.4-EVO versions earlier than 21.4R3-S8; * 22.1-EVO versions earlier than 22.1R3-S4; * 22.2-EVO versions earlier than 22.2R3-S3; * 22.3-EVO versions earlier than 22.3R3-S2; * 22.4-EVO versions earlier than 22.4R3; * 23.2-EVO versions earlier than 23.2R2.

Patch / fix

  • Juniper Networks Junos OS 20.4R3-S9, 21.2R3-S7, 21.3R3-S6, 21.4R3-S6, 22.1R3-S4, 22.2R3-S3, 22.3R3-S2, 22.4R3, 23.2R2
  • Juniper Networks Junos OS Evolved 21.2R3-S7-EVO, 21.3R3-S5-EVO, 21.4R3-S8-EVO, 22.1R3-S4-EVO, 22.2R3-S3-EVO, 22.3R3-S2-EVO, 22.4R3-EVO, 23.2R2-EVO, 23.4R1-EVO
  • juniper junos 20.4r3-s9, 21.2r3-s7, 21.3r3-s6, 21.4r3-s6, 22.1r3-s4, 22.2r3-s3, 22.3r3-s2, 22.4r3, 23.2r2
  • juniper junos_os_evolved 21.2r3-s7, 21.3r3-s5, 21.4r3-s8, 22.1r3-s4, 22.2r3-s3, 22.3r3-s2, 22.4r3, 23.2r2, 23.4r1

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.59% chance of exploitation in the next 30 days, higher than 48% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 4.0 8.7 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
CNA 4.0 8.7 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:A/V:X/RE:X/U:X

Affected products

  • Juniper Networks Junos OS
  • Juniper Networks Junos OS Evolved
  • juniper junos
  • juniper junos_os_evolved

Classification

Weakness
  • CWE-755 Improper Handling of Exceptional Conditions

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.