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UK Cyber Defence
VulnerabilityAnalyzed

CVE-2018-0172

Cisco IOS and IOS XE Software Improper Input Validation Vulnerability

KEVHIGH 8.6EPSS 7.82%

Does this matter?

Known to be exploited in the wild (CISA KEV, CISA remediation deadline 17 March 2022). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.

Description

A vulnerability in the DHCP option 82 encapsulation functionality of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. The vulnerability exists because the affected software performs incomplete input validation of option 82 information that it receives in DHCP Version 4 (DHCPv4) packets from DHCP relay agents. An attacker could exploit this vulnerability by sending a crafted DHCPv4 packet to an affected device. A successful exploit could allow the attacker to cause a heap overflow condition on the affected device, which will cause the device to reload and result in a DoS condition. Cisco Bug IDs: CSCvg62730.

CVSS 3.1
8.6 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
EPSS
7.82% probability · 94th percentile
CISA KEV
Listed 3 March 2022 · due 17 March 2022
Weakness
CWE-20, CWE-787
Affected
cisco/ios · cisco/ios xe
Source
psirt@cisco.com

CISA notes

Apply updates per vendor instructions. https://nvd.nist.gov/vuln/detail/CVE-2018-0172

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.