An Improper Handling of Exceptional Conditions vulnerability in the Routing Protocol Daemon (RPD) of Juniper Networks Junos OS and Junos OS Evolved allows an attacker sending a specific malformed BGP update message to cause the session to reset, resulting in a Denial of Service (DoS).  Continued receipt and processing of these malformed BGP update messages will create a sustained Denial of Service (DoS) condition.

Upon receipt of a BGP update message over an established BGP session containing a specifically malformed tunnel encapsulation attribute, when segment routing is enabled, internal processing of the malformed attributes within the update results in improper parsing of remaining attributes, leading to session reset:

BGP SEND Notification code 3 (Update Message Error) subcode 1 (invalid attribute list)

Only systems with segment routing enabled are vulnerable to this issue.

This issue affects eBGP and iBGP, in both IPv4 and IPv6 implementations, and requires a remote attacker to have at least one established BGP session.

This issue affects:

Junos OS: 


  *  All versions before 21.4R3-S8, 
  *  from 22.2 before 22.2R3-S4, 
  *  from 22.3 before 22.3R3-S3, 
  *  from 22.4 before 22.4R3-S3, 
  *  from 23.2 before 23.2R2-S1, 
  *  from 23.4 before 23.4R1-S2, 23.4R2.


Junos OS Evolved: 

  *  All versions before 21.4R3-S8-EVO, 
  *  from 22.2-EVO before 22.2R3-S4-EVO, 
  *  from 22.3-EVO before 22.3R3-S3-EVO, 
  *  from 22.4-EVO before 22.4R3-S3-EVO, 
  *  from 23.2-EVO before 23.2R2-S1-EVO, 
  *  from 23.4-EVO before 23.4R1-S2-EVO, 23.4R2-EVO.

Juniper 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/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

Juniper Networks, Inc. AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Juniper Networks, Inc. CWE-755

Juniper Networks, Inc. https://supportportal.juniper.net/JSA83015 [No types assigned]