SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2013-1147

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…

HIGH 7.8EPSS 1.33%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.33%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

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.

CVSS 2.0
7.8 HIGHAV:N/AC:L/Au:N/C:N/I:N/A:C
EPSS
1.33% probability · 71th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-119
Affected
cisco/ios
Source
psirt@cisco.com
EPSS trend
0%3%5%26 October 2026: 1.33%26 October 202626 October 2026

EPSS 1.3% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.