CVE-2017-12240
Cisco IOS and IOS XE Software DHCP Remote Code Execution Vulnerability
Published Sep 28, 2017 · updated Jun 16, 2026 · cisco ios
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.
Timeline
Detection, updates, and resolution for this record.
Sep 28, 2017 · Catalog
Detected
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
Mar 3, 2022 · CISA KEV
Known exploited
Apply updates per vendor instructions.
Mar 24, 2022 · CISA KEV
Remediation due
Apply updates per vendor instructions.
Jun 16, 2026 · Catalog
Updated
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
Required action
Apply updates per vendor instructions.
CISA due date Mar 24, 2022
Affected
- cpe cisco/iosversion unspecified
- vendor Cisco IOS and IOS XE Softwareversion unspecified
Sources
- CISA KEVCVE-2017-12240
The Dynamic Host Configuration Protocol (DHCP) relay subsystem of Cisco IOS 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.
cisa.gov - CVE.orgCVE-2017-12240
Official CVE identifier
cve.org - FIRST EPSSCVE-2017-12240
30-day exploitation probability 13.8%
first.org - NIST NVDCVE-2017-12240
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
nvd.nist.gov