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Fencer Vulns
high 7.5

CVE-2025-21598 json

Junos OS and Junos OS Evolved: When BGP traceoptions are configured, receipt of malformed BGP packets causes RPD to crash

published 2025-01-09 21 mo ago modified 2026-06-17 4 mo ago also EUVD-2025-2564

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.7%
EPSS 0.7% chance of exploitation in 30 days, percentile 54%
public exploits
0
none known

Summary

An Out-of-bounds Read vulnerability in Juniper Networks Junos OS and Junos OS Evolved's routing protocol daemon (rpd) allows an unauthenticated, network-based attacker to send malformed BGP packets to a device configured with packet receive trace options enabled to crash rpd. This issue affects:

Junos OS:

* from 21.2R3-S8 before 21.2R3-S9,  * from 21.4R3-S7 before 21.4R3-S9,  * from 22.2R3-S4 before 22.2R3-S5,  * from 22.3R3-S2 before 22.3R3-S4,  * from 22.4R3 before 22.4R3-S5,  * from 23.2R2 before 23.2R2-S2,  * from 23.4R1 before 23.4R2-S1,  * from 24.2R1 before 24.2R1-S1, 24.2R2.

Junos OS Evolved: * from 21.4R3-S7-EVO before 21.4R3-S9-EVO,  * from 22.2R3-S4-EVO before 22.2R3-S5-EVO,  * from 22.3R3-S2-EVO before 22.3R3-S4-EVO,  * from 22.4R3-EVO before 22.4R3-S5-EVO,  * from 23.2R2-EVO before 23.2R2-S2-EVO,  * from 23.4R1-EVO before 23.4R2-S1-EVO,  * from 24.2R1-EVO before 24.2R1-S2-EVO, 24.2R2-EVO.

This issue requires a BGP session to be established.

This issue can propagate and multiply through multiple ASes until reaching vulnerable devices.

This issue affects iBGP and eBGP.

This issue affects IPv4 and IPv6.

An indicator of compromise may be the presence of malformed update messages in a neighboring AS which is unaffected by this issue:

For example, by issuing the command on the neighboring device:  show log messages

Reviewing for similar messages from devices within proximity to each other may indicate this malformed packet is propagating:   rpd[<pid>]: Received malformed update from <IP address> (External AS <AS#>) and   rpd[<pid>]: Malformed Attribute

Patch / fix

  • Juniper Networks Junos OS 21.2R3-S9, 21.4R3-S9, 22.2R3-S5, 22.3R3-S4, 22.4R3-S5, 23.2R2-S2, 23.4R2-S1, 24.2R1-S1, 24.2R2
  • Juniper Networks Junos OS Evolved 21.4R3-S9-EVO, 22.2R3-S5-EVO, 22.3R3-S4-EVO, 22.4R3-S5-EVO, 23.2R2-S2-EVO, 23.4R2-S1-EVO, 24.2R1-S2-EVO, 24.2R2-EVO

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
21 mo ago

Exploit prediction

0.72% chance of exploitation in the next 30 days, higher than 54% 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 8.2 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/AU:Y/R:A/V:C/RE:M/U:Amber
CNA 4.0 8.2 CVSS:4.0/AV:N/AC:L/AT:P/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:Y/R:A/V:C/RE:M/U:Amber

Affected products

  • Juniper Networks Junos OS
  • Juniper Networks Junos OS Evolved

Classification

Weakness

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.