CVE-2011-4661: Cisco IOS

High severity, CVSS 7.5. EPSS: 1% chance of exploitation in the next 30 days.

A memory leak vulnerability exists in Cisco IOS before 15.2(1)T due to a memory leak in the HTTP PROXY Server process (aka CSCtu52820), when configured with Cisco ISR Web Security with Cisco ScanSafe and User Authenticaiton NTLM configured.

Affected products

• Cisco IOS: before 15.2\(1\)t (fixed in 15.2\(1\)t)

Published 2020-02-12. Last modified 2026-06-16.