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Actively exploited · Published Mar 28, 2018 · Assigned by cisco

CVE-2018-0173

High 8.6 Exploited

In plain English

A high-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 7.6% (higher than 95% of all known vulnerabilities). Apply updates per vendor instructions.

Severity (CVSS 3.1)8.6High
Exploit odds (30 days)7.6%top 5.4% 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 17, 2022.

Official description

A vulnerability in the Cisco IOS Software and Cisco IOS XE Software function that restores encapsulated option 82 information in DHCP Version 4 (DHCPv4) packets could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a Relay Reply denial of service (DoS) condition. The vulnerability exists because the affected software performs incomplete input validation of encapsulated option 82 information that it receives in DHCPOFFER messages from DHCPv4 servers. An attacker could exploit this vulnerability by sending a crafted DHCPv4 packet to an affected device, which the device would then forward to a DHCPv4 server. When the affected software processes the option 82 information that is encapsulated in the response from the server, an error could occur. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. Cisco Bug IDs: CSCvg62754.

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:C/C:N/I:N/A:H

References