CVE-2011-4661

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.0% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2020-02-12 · updated 2026-06-16
Weakness: CWE-772

Description

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

How to fix

Upgrade to a fixed version: Cisco IOS 15.2\(1\)t. Check the vendor advisory for mitigations.

References

https://www.cisco.com/c/en/us/td/docs/ios/15_2m_and_t/release/notes/15_2m_and_t/152-1TCAVS.html
https://www.cisco.com/c/en/us/td/docs/ios/15_2m_and_t/release/notes/15_2m_and_t/152-1TCAVS.html

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