CVE-2014-3347: Cisco 1801 Integrated Service Router

Medium severity, CVSS 5.4. EPSS: 1% chance of exploitation in the next 30 days.

Cisco IOS 15.1(4)M2 on Cisco 1800 ISR devices, when the ISDN Basic Rate Interface is enabled, allows remote attackers to cause a denial of service (device hang) by leveraging knowledge of the ISDN phone number to trigger an interrupt timer collision during entropy collection, leading to an invalid state of the hardware encryption module, aka Bug ID CSCul77897.

Affected products

• Cisco 1801 Integrated Service Router
• Cisco 1802 Integrated Service Router
• Cisco 1803 Integrated Service Router
• Cisco 1811 Integrated Service Router
• Cisco 1812 Integrated Service Router
• Cisco 1841 Integrated Service Router
• Cisco 1861 Integrated Service Router
• Cisco IOS: version 15.1(4)m2 only

Published 2014-08-28. Last modified 2026-06-17.