CVE-2018-0172
Published: March 3, 2022
Official Description
A vulnerability in the DHCP option 82 encapsulation functionality of Cisco IOS Software and Cisco IOS XE Software could allow for denial-of-service (DoS).
CISA KEV Advisory
Cisco IOS and IOS XE Software Improper Input Validation Vulnerability
A vulnerability in the DHCP option 82 encapsulation functionality of Cisco IOS Software and Cisco IOS XE Software could allow for denial-of-service (DoS).
Apply updates per vendor instructions.
Risk Analysis
This vulnerability in the DHCP option 82 encapsulation functionality of Cisco IOS Software and Cisco IOS XE Software could allow for denial-of-service (DoS). It is a high-severity flaw and is urgent due to its inclusion in CISA's KEV catalog, confirming active exploitation. The EPSS score of 0.05888 indicates a moderate likelihood of exploitation.
This vulnerability is actively exploited in the wild and is listed in CISA's KEV catalog, confirming its use by attackers.
Apply available updates and patches for Cisco IOS Software and Cisco IOS XE Software. Review and configure DHCP option 82 settings to mitigate potential DoS attacks.
Technical Analysis
CVE-2018-0172 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
CISA has added CVE-2018-0172 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.
Affected Vendors & Products
Exploit & PoC Resources
All References (1)
Quick Facts
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2018-0172 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
- !CISA KEV: Federal agencies must patch per BOD 22-01 timeline
- !Active exploitation confirmed — treat as P1