Vulnerabilities > CVE-2021-0239 - Improper Check for Unusual or Exceptional Conditions vulnerability in Juniper Junos OS Evolved 20.4

Summary

In Juniper Networks Junos OS Evolved, receipt of a stream of specific genuine Layer 2 frames may cause the Advanced Forwarding Toolkit (AFT) manager process (Evo-aftmand), responsible for handling Route, Class-of-Service (CoS), Firewall operations within the packet forwarding engine (PFE) to crash and restart, leading to a Denial of Service (DoS) condition. By continuously sending this specific stream of genuine Layer 2 frames, an attacker can repeatedly crash the PFE, causing a sustained Denial of Service (DoS). This issue affects Juniper Networks Junos OS Evolved: All versions prior to 20.4R1-EVO. This issue does not affect Junos OS versions.

Vulnerable Configurations

Common Weakness Enumeration (CWE)

• CWE-754 - Improper Check for Unusual or Exceptional Conditions

References