An Improper Input Validation vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS Evolved allows a local, low-privileged attacker to cause a Denial of Service (DoS).

When a specific "clear" command is run, the Advanced Forwarding Toolkit manager (evo-aftmand-bt or evo-aftmand-zx) crashes and restarts.

The crash impacts all traffic going through the FPCs, causing a DoS. Running the command repeatedly leads to a sustained DoS condition.
 

This issue affects Junos OS Evolved: 

• All versions before 20.4R3-S9-EVO, 
• from 21.2-EVO before 21.2R3-S7-EVO, 
• from 21.3-EVO before 21.3R3-S5-EVO, 
• from 21.4-EVO before 21.4R3-S6-EVO, 
• from 22.1-EVO before 22.1R3-S4-EVO, 
• from 22.2-EVO before 22.2R3-S3-EVO, 
• from 22.3-EVO before 22.3R3-S3-EVO, 
• from 22.4-EVO before 22.4R3-EVO,
• from 23.2-EVO before 23.2R2-EVO.

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: 20.4R3-S9-EVO, 21.2R3-S7-EVO, 21.3R3-S5-EVO, 21.4R3-S6-EVO, 22.1R3-S4-EVO, 22.2R3-S3-EVO, 22.3R3-S3-EVO, 22.4R3-EVO, 23.2R2-EVO, 23.4R1-EVO, and all subsequent releases.

This issue is being tracked as 1760052 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).

There are no known workarounds for this issue.

To reduce the risk of exploitation, limit access to the device only from trusted administrative networks, users and hosts.

2024-07-10: Initial Publication
2024-09-13: Minor formatting change to CVSS field

• 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.cve.org/CVERecord?id=CVE-2024-39513