Vulnerability record

CVE-2017-12240

Cisco IOS and IOS XE Software DHCP Remote Code Execution Vulnerability

Severity: CriticalExploitation: Exploitation confirmedCISA KEV
What should I do?

This vulnerability is in the CISA Known Exploited Vulnerabilities catalog: attackers are using it. If you run IOS and IOS XE Software, fix it now.

CISA required action: Apply updates per vendor instructions.

US federal civilian agencies must remediate by Mar 24, 2022.

Patch status

No official fix confirmed yet

Until a fix ships, follow the vendor's mitigations and CISA's required action, limit exposure of affected systems, and watch this record for a patch.

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.

Source: NIST National Vulnerability Database. Official vulnerability data, reproduced as published.

Affected products

Products affected by this vulnerability, with versions and the source of each entry
ProductVendorAffected versionsSource
IOSCisco>= 12.2, <= 15.6NVD
IOS and IOS XE SoftwareCisco—KEV

Sources: NVD = NIST National Vulnerability Database; KEV = CISA Known Exploited Vulnerabilities catalog.

Intelligence timeline

Developments from the last 30 days, newest first.

  1. CVSS scoredUpdateKEV

    CVE-2017-12240 scored CVSS 9.8: Cisco IOS and IOS XE Software, Cisco IOS and IOS XE Software DHCP Remote Code Execution Vulnerability

    CISA lists this as exploited in the wild. Unpatched IOS and IOS XE Software systems are exposed to active attacks now.

    Basis: NIST National Vulnerability Database

1 earlier event is available with a subscription. See plans.

Coverage

We have not published a story about this vulnerability yet.

References