CVE-2015-6271: Cisco IOS XE

High severity, CVSS 7.8. EPSS: 2% chance of exploitation in the next 30 days.

Cisco IOS XE 2.1.0 through 2.4.3 and 2.5.0 on ASR 1000 devices, when NAT Application Layer Gateway is used, allows remote attackers to cause a denial of service (Embedded Services Processor crash) via a crafted SIP packet, aka Bug IDs CSCta74749 and CSCta77008.

Affected products

• Cisco IOS XE: version 2.1.0 only; version 2.1.1 only; version 2.1.2 only; version 2.1.3 only; version 2.2.1 only; version 2.2.2 only; …

Published 2015-08-31. Last modified 2026-06-17.