CVE-2013-1147: Cisco IOS

High severity, CVSS 7.8. EPSS: 1.3% chance of exploitation in the next 30 days.

The Protocol Translation (PT) functionality in Cisco IOS 12.3 through 12.4 and 15.0 through 15.3, when one-step port-23 translation or a Telnet-to-PAD ruleset is configured, does not properly validate TCP connection information, which allows remote attackers to cause a denial of service (device reload) via an attempted connection to a PT resource, aka Bug ID CSCtz35999.

Affected products

• Cisco IOS: version 12.3 only; version 12.4 only; version 15.0 only; version 15.1 only; version 15.2 only; version 15.3 only

Published 2013-03-28. Last modified 2026-06-16.