An Improper Check for Unusual or Exceptional Conditions vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on QFX10000 Series allows a network based attacker to cause a Denial of Service (DoS).

If a specific valid IP packet is received and that packet needs to be routed over a VXLAN tunnel, this will result in a PFE wedge condition due to which traffic gets impacted. As this is not a crash and restart scenario, this condition will persist until the system is rebooted to recover.
 

This issue affects Juniper Networks Junos OS on QFX10000:

• 20.3 version 20.3R1 and later versions;
• 20.4 versions prior to 20.4R3-S5;
• 21.1 versions prior to 21.1R3-S5;
• 21.2 versions prior to 21.2R3-S5;
• 21.3 versions prior to 21.3R3-S4;
• 21.4 versions prior to 21.4R3-S1;
• 22.1 versions prior to 22.1R3;
• 22.2 versions prior to 22.2R2;
• 22.3 versions prior to 22.3R1-S2, 22.3R2.

To be exposed to this issue the QFX device needs be configured for VXLAN with either of the following statements:

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

This issue was seen during production usage.

This issue has been assigned CVE-2023-36835.

The following software releases have been updated to resolve this specific issue: 20.4R3-S5, 21.1R3-S5, 21.2R3-S5, 21.3R3-S4, 21.4R3-S1, 22.1R3, 22.2R2, 22.3R1-S2, 22.3R2, 22.4R1, and all subsequent releases.
 

This issue is being tracked as 1678992

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

2023-07-12: 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
• CVE-2023-36835 at www.cve.org