CVE-2017-12240

9.8 CRITICAL CISA KEV - Actively Exploited
Published: September 29, 2017 Modified: October 22, 2025

Description

The DHCP relay subsystem of Cisco IOS 12.2 through 15.6 and Cisco IOS XE Software contains a vulnerability that could allow an unauthenticated, remote attacker to execute arbitrary code and gain full control of an affected system. The attacker could also cause an affected system to reload, resulting in a denial of service (DoS) condition. The vulnerability is due to a buffer overflow condition in the DHCP relay subsystem of the affected software. An attacker could exploit this vulnerability by sending a crafted DHCP Version 4 (DHCPv4) packet to an affected system. A successful exploit could allow the attacker to execute arbitrary code and gain full control of the affected system or cause the affected system to reload, resulting in a DoS condition. Cisco Bug IDs: CSCsm45390, CSCuw77959.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
http://www.securityfocus.com/bid/101034
Source: psirt@cisco.com
Broken Link Third Party Advisory VDB Entry
http://www.securitytracker.com/id/1039445
Source: psirt@cisco.com
Broken Link Third Party Advisory VDB Entry
http://www.securityfocus.com/bid/101034
Source: af854a3a-2127-422b-91ae-364da2661108
Broken Link Third Party Advisory VDB Entry
http://www.securitytracker.com/id/1039445
Source: af854a3a-2127-422b-91ae-364da2661108
Broken Link Third Party Advisory VDB Entry
https://quickview.cloudapps.cisco.com/quickview/bug/CSCsm45390
Source: af854a3a-2127-422b-91ae-364da2661108
Vendor Advisory
https://quickview.cloudapps.cisco.com/quickview/bug/CSCuw77959
Source: af854a3a-2127-422b-91ae-364da2661108
Vendor Advisory

11 reference(s) from NVD

Quick Stats

CVSS v3 Score
9.8 / 10.0
EPSS (Exploit Probability)
21.8%
96th percentile
Exploitation Status
Actively Exploited
Remediation due: 2022-03-24

Weaknesses (CWE)

Affected Vendors

cisco