CVE-2024-20451: Cisco Spa 301 Firmware

High severity, CVSS 7.5. EPSS: 0.8% chance of exploitation in the next 30 days.

Multiple vulnerabilities in the web-based management interface of Cisco Small Business SPA300 Series IP Phones and Cisco Small Business SPA500 Series IP Phones could allow an unauthenticated, remote attacker to cause an affected device to reload unexpectedly. These vulnerabilities exist because HTTP packets are not properly checked for errors. An attacker could exploit this vulnerability by sending a crafted HTTP packet to the remote interface of an affected device. A successful exploit could allow the attacker to cause a DoS condition on the device.

Affected products

• Cisco Spa 301 Firmware: any version
• Cisco Spa 303 Firmware: any version
• Cisco Spa 501g Firmware: any version
• Cisco Spa 502g Firmware: any version
• Cisco Spa 504g Firmware: any version
• Cisco Spa 508g Firmware: any version
• Cisco Spa 509g Firmware: any version
• Cisco Spa 512g Firmware: any version
• Cisco Spa 514g Firmware: any version
• Cisco Spa 525g2 Firmware: any version
• Cisco Spa 525g Firmware: any version

Published 2024-08-07. Last modified 2026-06-17.