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 execute arbitrary commands on the underlying operating system with root privileges. These vulnerabilities exist because incoming HTTP packets are not properly checked for errors, which could result in a buffer overflow. An attacker could exploit this vulnerability by sending a crafted HTTP request to an affected device. A successful exploit could allow the attacker to overflow an internal buffer and execute arbitrary commands at the root privilege level.
Conclusion & alert: CVE-2024-20454 is rated High Risk (66.7/100): CVSS Critical severity, with high exploitation likelihood (EPSS 6.52%, 93th percentile). Core evidence: EPSS ranks this CVE among the most likely to be exploited in the near term. Mandatory action: High exploitation likelihood—assess exposure and prioritize remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-15 | 11.71% | 6.52% | -5.19% |
| 2 | 2026-03-16 | 22.93% | 11.71% | -11.22% |
| 3 | 2026-02-10 | — | 22.93% | — |
Full EPSS history (17 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 9.8 | 3.1 | CRITICAL |
|
3.9 | 5.9 | [email protected] |
| 9.8 | 3.1 | CRITICAL |
|
3.9 | 5.9 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| cisco | spa_301_firmware | — | cpe:2.3:o:cisco:spa_301_firmware:*:*:*:*:*:*:*:* |
| cisco | spa_303_firmware | — | cpe:2.3:o:cisco:spa_303_firmware:*:*:*:*:*:*:*:* |
| cisco | spa_501g_firmware | — | cpe:2.3:o:cisco:spa_501g_firmware:*:*:*:*:*:*:*:* |
| cisco | spa_502g_firmware | — | cpe:2.3:o:cisco:spa_502g_firmware:*:*:*:*:*:*:*:* |
| cisco | spa_504g_firmware | — | cpe:2.3:o:cisco:spa_504g_firmware:*:*:*:*:*:*:*:* |
| cisco | spa_508g_firmware | — | cpe:2.3:o:cisco:spa_508g_firmware:*:*:*:*:*:*:*:* |
| cisco | spa_509g_firmware | — | cpe:2.3:o:cisco:spa_509g_firmware:*:*:*:*:*:*:*:* |
| cisco | spa_512g_firmware | — | cpe:2.3:o:cisco:spa_512g_firmware:*:*:*:*:*:*:*:* |
| cisco | spa_514g_firmware | — | cpe:2.3:o:cisco:spa_514g_firmware:*:*:*:*:*:*:*:* |
| cisco | spa_525g_firmware | — | cpe:2.3:o:cisco:spa_525g_firmware:*:*:*:*:*:*:*:* |
| cisco | spa_525g2_firmware | — | cpe:2.3:o:cisco:spa_525g2_firmware:*:*:*:*:*:*:*:* |