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Fencer Vulns
high 7.5

CVE-2024-21598 json

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

published 2024-04-12 2 y ago modified 2026-06-17 4 mo ago also EUVD-2024-19246

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 47%
public exploits
0
none known

Summary

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.

Patch / fix

  • Juniper Networks Junos OS 20.4R3-S9, 21.2R3-S7, 21.3R3-S5, 21.4R3-S5, 22.1R3-S4, 22.2R3-S3, 22.3R3-S1, 22.4R3, 23.2R1-S2, 23.2R2
  • Juniper Networks Junos OS Evolved 20.4R3-S9-EVO, 21.2R3-S7-EVO, 21.3R3-S5-EVO, 21.4R3-S5-EVO, 22.1R3-S4-EVO, 22.2R3-S3-EVO, 22.3R3-S1-EVO, 22.4R3-EVO, 23.2R1-S2-EVO, 23.2R2-EVO
  • juniper_networks junos_os 20.4r3-s9, 21.2r3-s7, 21.3r3-s5, 21.4r3-s5, 22.1r3-s4, 22.2r3-s3, 22.3r3-s1, 22.4r3, 23.2r1-s2
  • juniper junos_os_evolved 20.4r3-s9, 21.2r3-s7, 21.3r3-s5, 21.4r3-s4, 22.1r3-s4, 22.2r3-s3

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.57% chance of exploitation in the next 30 days, higher than 47% 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
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:X/V:X/RE:X/U:X

Affected products

  • Juniper Networks Junos OS
  • Juniper Networks Junos OS Evolved
  • juniper_networks junos_os
  • juniper junos_os_evolved

Classification

Weakness
  • CWE-1286 Improper Validation of Syntactic Correctness of Input

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.