CVE-2009-20009: Belkin International, Inc Bulldog Plus Ups Monitoring Software

Critical severity, CVSS 9.3. EPSS: 1.3% chance of exploitation in the next 30 days.

Belkin Bulldog Plus version 4.0.2 build 1219 contains a stack-based buffer overflow vulnerability in its web service authentication handler. When a specially crafted HTTP request is sent with an oversized Authorization header, the application fails to properly validate the input length before copying it into a fixed-size buffer, resulting in memory corruption and potential remote code execution. Exploitation requires network access and does not require prior authentication.

Affected products

• Belkin International, Inc Bulldog Plus Ups Monitoring Software: up to and including 4.0.2 build 1219

Published 2025-08-30. Last modified 2026-10-01.