CVE-2022-0028

CVE-2022-0028 is a critical vulnerability in Palo Alto Networks PAN-OS that allows for reflected and amplified TCP denial-of-service (RDoS) attacks. This misconfiguration affects PA-Series, VM-Series, and CN-Series firewalls when a URL filtering profile with blocked categories is assigned to an external-facing source zone. The vulnerability has a CVSS score of 8.6 (High) due to its network-based attack vector, low complexity, and high impact on availability for the targeted victim, though it does not compromise the firewall itself. This flaw is actively exploited in the wild, as confirmed by its inclusion in CISA's KEV catalog, and has garnered significant community discussion and media attention, despite no public exploit code being readily available.