CVE-2025-21598 Information

Description

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[]: Received malformed update from (External AS ) and   rpd[]: Malformed Attribute

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Reference

https://supportportal.juniper.net/JSA92867 https://www.juniper.net/documentation/us/en/software/junos/cli-reference/topics/ref/statement/traceoptions-edit-protocols-bgp.html

Attack Complexity

LOW

Privileges Required

NONE

User Interaction Required

NONE

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

NONE

Availability Impact

NONE

Base Score

HIGH

Base Severity

7.5