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4.3
Cisco Firewalls: OSPF Attack Can Crash Device
CVE-2026-20021
Summary
This is a security issue affecting Cisco Firewalls. An attacker can send a specific type of packet to the firewall, which can cause it to run out of memory and stop working. To protect your device, Cisco recommends upgrading to the latest software version or applying a patch.
Original title
A vulnerability in the OSPF protocol of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an authenticated, adjace...
Original description
A vulnerability in the OSPF protocol of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an authenticated, adjacent attacker to exhaust memory on an affected device, resulting in a denial of service (DoS) condition.
This vulnerability is due to improperly validating input by the OSPF protocol when parsing packets. An attacker could exploit this vulnerability by by sending crafted OSPF packets to an affected device. A successful exploit could allow the attacker to exhaust memory on the affected device, resulting in a DoS condition.
This vulnerability is due to improperly validating input by the OSPF protocol when parsing packets. An attacker could exploit this vulnerability by by sending crafted OSPF packets to an affected device. A successful exploit could allow the attacker to exhaust memory on the affected device, resulting in a DoS condition.
nvd CVSS3.1
4.3
Vulnerability type
CWE-401
Memory Leak
Published: 4 Mar 2026 · Updated: 13 Mar 2026 · First seen: 6 Mar 2026