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Actively exploited · Published Sep 28, 2017 · Assigned by cisco

CVE-2017-12240

Critical 9.8 Exploited

In plain English

A critical-severity improper input validation in Cisco IOS and IOS XE. Attackers are actively exploiting it in the wild (listed by CISA on March 3, 2022). The chance it is exploited in the next 30 days is estimated at 13.8% (higher than 97% of all known vulnerabilities). Apply updates per vendor instructions.

Severity (CVSS 3.1)9.8Critical
Exploit odds (30 days)13.8%top 3.5% of all CVEs
Exploited in the wildYesCISA KEV since Mar 3, 2022
Attack toolingNoneno public tooling known

CISA guidance

Apply updates per vendor instructions.

Federal agencies must remediate by Mar 24, 2022.

Official 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.

Affected products (as reported)

VendorProductVersions
n/a Cisco IOS and IOS XE Cisco IOS and IOS XE

Weakness: CWE-20 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References