CVE-2015-0731: Cisco IOS

Medium severity, CVSS 6.1. EPSS: 0.6% chance of exploitation in the next 30 days.

The ISDN implementation in Cisco IOS 15.3S allows remote attackers to cause a denial of service (device reload) via malformed Q931 SETUP messages, aka Bug ID CSCut37890.

Affected products

• Cisco IOS: version 15.3(3)s1 only; version 15.3s only

Published 2015-05-16. Last modified 2026-06-17.