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

Required configuration for exposure:

This issue can occur when BGP trace options are enabled at global, group, or neighbor-level.

The following global example is provided:
  [protocols bgp traceoptions flag update detail]
or
  [protocols bgp traceoptions flag receive detail]
and
  [protocols bgp traceoptions flag update detail]
  [protocols bgp traceoptions flag receive detail]

The following neighbor-level example is provided:
  [protocols bgp group test neighbor 192.168.1.1 traceoptions flag update detail]
  [protocols bgp group test neighbor 192.168.1.1 traceoptions flag receive detail]

Refer to your product documentation for other examples and configurations.

Juniper SIRT is not aware of any malicious exploitation of this vulnerability.

This issue was seen during production usage.

The following software releases have been updated to resolve this specific issue:

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, 24.4R1, and all subsequent releases.

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, 24.4R1-EVO, and all subsequent releases.

This issue is being tracked as 1821241 which is visible on the Customer Support website.

Note: Juniper SIRT's policy is not to evaluate releases which are beyond End of Engineering (EOE) or End of Life (EOL).

Disabling packet tracing options will work around this issue.

There are no other available workarounds for this issue.

2025-01-08: Initial Publication

• KB16613: Overview of the Juniper Networks SIRT Quarterly Security Bulletin Publication Process [juniper.net]
• KB16765: In which releases are vulnerabilities fixed? [juniper.net]
• KB16446: Common Vulnerability Scoring System (CVSS) and Juniper's Security Advisories [juniper.net]
• Report a Security Vulnerability - How to Contact the Juniper Networks Security Incident Response Team
• https://www.juniper.net/documentation/us/en/software/junos/cli-reference/topics/ref/statement/traceoptions-edit-protocols-bgp.html