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Case File

CVE-2017-12240

CRITICAL · CVSS 9.8 EPSS 13.88% CISA KEV · Actively Exploited Public Exploit

Source: NVD + CISA KEV + EPSS (historical backfill) · Published 2017-09-29 · Last synced 2026-08-04

Field Assessment

AI analysis pending.

Exhibit — Public Exploit Signal

A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.

Detected Signals
exploit

Note: these links are listed for security research and verification purposes only.

Cross-Reference — CISA KEV

Status: This CVE is listed in CISA's Known Exploited Vulnerabilities catalog.

Ransomware use: Unknown

Added to KEV: 2022-03-03

Required action: Apply updates per vendor instructions.

CVE
CVE-2017-12240
Severity
CRITICAL
CVSS
9.8
EPSS
13.88%
Cisco

Original Filing — NVD 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.